Category: Class 10

Students can download 10th Science Chapter 9 Solutions Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 9 Solutions

Samacheer Kalvi 10th Science Solutions Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
A solution is a mixture.
(a) homogeneous
(b) heterogeneous
(c) homogeneous and heterogeneous
(d) non-homogeneous
Answer:
(a) homogeneous

Question 2.
The number of components in a binary solution is ______.
(a) 2
(b) 3
(c) 4
(d) 5.
Answer:
(a) 2

Question 3.
Which of the following is the universal solvent?
(a) Acetone
(b) Benzene
(c) Water
(d) Alcohol
Answer:
(c) Water

Question 4.
A solution in which no more solute can be dissolved in a definite amount of solvent at a given temperature is called ______.
(a) Saturated solution
(b) Un saturated solution
(c) Supersaturated solution
(d) Dilute solution.
Answer:
(a) Saturated solution

Question 5.
Identify the non-aqueous solution.
(a) sodium chloride in water
(b) glucose in water
(c) copper sulphate in water
(d) sulphur in carbon-di-sulphide
Answer:
(d) sulphur in carbon-di-sulphide

Question 6.
When pressure is increased at a constant temperature the solubility of gases in liquid ______.
(a) No change
(b) increases
(c) decreases
(d) no reaction.
Answer:
(b) increases

Question 7.
Solubility of NaCl in 100 ml water is 36 g. If 25 g of salt is dissolved in 100 ml of water how much more salt is required for saturation:
(a) 12 g
(b) 11 g
(c) 16 g
(d) 20 g
Answer:
(b) 11 g

Question 8.
A 25% alcohol solution means ______.
(a) 25 ml of alcohol in. 100 ml of water
(b) 25 ml of alcohol in 25 ml of water
(c) 25 ml of alcohol in 75 ml of water
(d) 75 ml of alcohol in 25 ml of water.
Answer:
(c) 25 ml of alcohol in 75 ml of water

Question 9.
Deliquescence is due to:
(a) Strong affinity to water
(b) Less affinity to water
(c) Strong hatred to water
(d) Inertness to water
Answer:
(a) Strong affinity to water

Question 10.
Which of the following is hygroscopic in nature?
(a) ferric chloride
(b) copper sulphate pentahydrate
(c) silica gel
(d) none of the above.
Answer:
(c) silica gel

II. Fill in the blanks:

1. The component present in lesser amount, in a solution is called ……..
2. Example for liquid in solid type solution is ……….
3. Solubility is the amount of solute dissolved in ……… g of solvent.
4. Polar compounds are soluble in ……… solvents.
5. Volume percentage decreases with increases in temperature because ………

Answer:

1. solute
2. amalgam
3. 100
4. Polar
5. of expansion of liquid

III. Match the following:

Answer:
A. (iii)
B. (i)
C. (iv)
D. (ii)

IV. True or False: (If false give the correct statement):

1. Solutions which contain three components are called binary solution.
2. In a solution the component which is present in lesser amount is called solvent.
3. Sodium chloride dissolved in water forms a non-aqueous solution.
4. The molecular formula of green vitriol is MgSO₄. 7H₂O
5. When Silica gel is kept open, it absorbs moisture from the air, because it is hygroscopic in nature.

Answer:

1. False – Solutions which contain two components are called binary solution.
2. False – In a solution the component which is present in lesser amount is called solute.
3. False – Sodium chloride dissolved in water forms an aqueous solution.
4. False – The molecular formula of green vitriol is FeSO₄. 7H₂O
5. True

V. Short Answer Questions:

Question 1.
Define the term: Solution
Answer:
A solution is a homogeneous mixture of two or more substances.

Question 2.
What is mean by the binary solution?
Answer:
A solution must at least be consisting of two components. Such solutions which are made of one solute and one solvent are called binary solutions.
E.g., On adding CuSO₄ crystals to water.

Question 3.
Give an example each

1. gas in liquid;
2. solid in liquid;
3. solid in solid;
4. gas in gas.

Answer:

1. Gas in liquid – CO₂ in water
2. Solid in liquid – NaCl in water
3. Solid in solid – Alloys
4. Gas in gas – He – O₂ gas

Question 4.
What is the aqueous and non-aqueous solution? Give an example.
Answer:
Aqueous solution: The solution in which water act as a solvent is called aqueous solution. In general, ionic compounds are soluble in water and form aqueous solutions more readily than covalent compounds. E.g. Common salt in water.

Non – Aqueous solution: The solution in which any liquid, other than water act as a solvent is called non-aqueous solution. Alcohols, benzene, ethers, etc., are used as non – aqueous solvents. E.g. Sulphur dissolved in carbon disulphide.

Question 5.
Define Volume percentage.
Answer:
Volume percentage is defined as the percentage by volume of solute (in ml) present in the given volume of solution.

Question 6.
The aquatic animals live more in a cold region. Why?
Answer:
Aquatic animals live more in cold regions because the solubility of oxygen is more in cold water (at low temperature). Therefore, aquatic animals are more comfortable in cold water.

Question 7.
Define Hydrated salt.
Answer:
Ionic substances which crystallise out from their saturated aqueous solution with a definite number of molecules of water are called hydrated salts.

Question 8.
A hot saturated solution of copper sulphate forms crystals as it cools. Why?
Answer:
The capability of a solution to maintain a certain concentration of solute is temperature-dependent. When a saturated solution of copper sulphate at above room temperature is allowed to cool, the solution becomes supersaturated and in the absence of stirring or the return of the previous solution temperature, the solute starts to precipitate out. i.e., crystal formation occurs.

Question 9.
Classify the following substances into deliquescent, hygroscopic. Cone. Sulphuric acid, Copper sulphate penta hydrate, Silica gel, Calcium chloride and Gypsum salt.
Answer:

VI. Long answer questions:

Question 1.
Write notes on?

1. saturated solution
2. unsaturated solution

Answer:

1. Saturated solution: A solution in which no more solute can be dissolved in a definite amount of the solvent at a given temperature is called saturated solution, e.g. 36 g of sodium chloride in 100 g of water at 25°C forms a saturated solution.
2. Unsaturated solution: Unsaturated solution is one that contains less solute than that of the saturated solution at a given temperature, e.g. 10 g or 20 g or 30 g of Sodium chloride in 100 g of water at 25°C forms an unsaturated solution.

Question 2.
Write notes on various factors affecting solubility.
Answer:
There are three main factors which affects the solubility of a solute. They are

1. Nature of the solute and solvent
2. Temperature
3. Pressure

1. Nature of the solute and solvent : The nature of the solute and solvent plays an important role in solubility. Even though water is Universal solvent, all substances do not dissolve in water. Dissolution occurs when similarities exist between the solvent and the solute.

Ionic compounds are soluble in polar solvent like water and covalent compounds are soluble in non-polar solvents like ether, benzene, alcohol etc.

2. Effect of Temperature :
Solubility of solid in liquid : Generally solubility of a solid solute in a liquid increases with increase in temperature.
In Endothermic process : Solubility increases with increase in temperature.
In Exothermic process : Solubility decreases with increase in temperature.
Solubility of Gases in liquid : Solubility of gases in liquid decreases with increase in temperature.

3. Effect of Pressure : Effect of pressure is observed only in the case of solubility of a gas in a liquid. When the pressure is increased, the solubility of a gas in liquid increases.

Question 3.
(a) What happens when MgSO₄.7H₂O is heated? Write the appropriate equation
(b) Define solubility.
Answer:
(a) When Epsom salt MgSO₄.7H₂O crystals are gently heated, it loses seven water molecules and becomes anhydrous MgSO₄.

(b) Solubility is defined as the amount of solute in grams that can be dissolved in 100 g of the solvent to form its saturated solution at a given temperature and pressure.

Question 4.
In what way hygroscopic substances differ from deliquescent substances.
Answer:

Question 5.
A solution is prepared by dissolving 45 g of sugar in 180 g of water. Calculate the mass percentage of solute.
Answer:
Mass of the solute (sugar) = 45 g
Mass of the solvent (Water) = 180 g
Formula:
Mass percentage of solute (sugar)

The mass percentage of solute = 20%

Question 6.
3.5 litres of ethanol is present in 15 litres of aqueous solution of ethanol. Calculate volume percent of ethanol solution.
Answer:
Volume of ethanol = 3.5 lit = 3500 ml
Volume of water = 15 lit = 15000 ml
Formula:

The volume percentage of ethanol solution = 18.92

VII. HOT Questions

Question 1.
Vinu dissolves 50 g of sugar in 250 ml of hot water, Sarath dissolves 50 g of same sugar in 250 ml of cold water. Who will get a faster dissolution of sugar? and Why?
Answer:
Vinu will get a faster dissolution of sugar. Because generally solubility of a solid solute in a liquid solvent increases with increase in temperature. Therefore Vinu dissolves 50 g of sugar in 250 ml of hot water than Sarath dissolves 50 g of sugar in 250 ml of cold water.

Question 2.
‘A’ is a blue coloured crystalline salt. On heating it loses blue colour and to give ‘B’ When water is added, ‘B’ gives back to ‘A’. Identify A and B, write the equation.
Answer:
Since ‘A’ is a blue coloured crystalline salt, it is CuSO₄. 5H₂O (Blue vitriol). On heating it loses all five water molecules and becomes colourless anhydrous CuSO₄.

When water is added ‘B’ gives back A.

Question 3.
Will the cool drinks give more fizz at top of the hills or at the foot? Explain.
Answer:
At hilltops, the temperature will become less and pressure also decreases. Because temperature and pressure are directly proportional to each other. At low-pressure carbonate, cool drinks will give less fizz and give more fizz at the foot.

Samacheer Kalvi 10th Science Solutions Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The dissolution of sugar and salt in water results in a solution.
(a) Binary
(b) Ternary
(c) Quaternary
(d) Saturated
Answer:
(b) Ternary

Question 2.
In a solution, the component which is present in a lesser amount is called ______.
(a) solvent
(b) dissolution
(c) solute
(d) mole.
Answer:
(c) solute

Question 3.
The supersaturated solution of NaCl in 100 g of water at 25°C contains:
(a) 40 g of NaCl
(b) 10 g of NaCl
(c) 20 g of NaCl
(d) 30 g of NaCl
Answer:
(a) 40 g of NaCl

Question 4.
How many component(s) present in binary solution?
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(b) 2

Question 5.
Formalin is an aqueous solution of:
(a) formic acid
(b) ammonia
(c) formaldehyde
(d) carbon tetrachloride
Answer:
(c) formaldehyde

Question 6.
The effect of pressure on the solubility of a gas in liquids is given by:
(a) Boyle’s Law
(b) Charle’s Law
(c) Henry’s Law
(d) Avogadro’s Law
Answer:
(c) Henry’s Law

Question 7.
Which one of the following is an example of an aqueous solution?
(a) Sugar in water
(b) Sulphur in carbon disulphide
(c) Iodine dissolved in carbon tetrachloride
(d) Benzoic acid in ethers.
Answer:
(a) Sugar in water

Question 8.
The type of solution when CO₂ is dissolved in water:
(a) solid/liquid
(b) liquid in liquid
(c) gas in liquid
(d) liquid in solid
Answer:
(c) gas in liquid

Question 9.
Tin amalgam is an example of ……… solution.
(a) solid in solid
(b) liquid in solid
(c) solid in liquid
(d) liquid in liquid
Answer:
(b) liquid in solid

Question 10.
In which case solubility decreases with increase in temperature?
(a) Endothermic process
(b) Exothermic process
(c) Both (a) and (b)
(d) None of these.
Answer:
(b) Exothermic process

Question 11.
Fat is soluble in:
(a) water
(b) alcohol
(c) CCl₄
(d) ether
Answer:
(d) ether

Question 12.
The deliquescent substance among the following is:
(a) con.H₂SO₄
(b) P₂O₅
(c) CaCl₂
(d) SiO₂
Answer:
(c) CaCl₂

Question 13.
Mass percentage is expressed as ______.
(a) v/v
(b) w/w
(c) v/w
(d) w/v.
Answer:
(b) w/w

Question 14.
Hygroscopic substances are used as ……… agents.
(a) foaming
(b) drying
(c) oxidising
(d) reducing
Answer:
(b) drying

Question 15.
The molecular formula of Epsom salt is ______.
(a) CuSO₄.5H₂O
(b) FeSO₄.7H₂O
(c) MgSO₄.7H₂O
(d) ZnSO₄.7H₂O.
Answer:
(c) MgSO₄.7H₂O

II. Fill in the blanks:

1. A true solution is a ……… mixture of solute and solvent.
2. Soil cannot store more nitrogen than it can hold because soil is said to be in a state of ………
3. In the dissolution of NaOH in water, the solubility …….. with increase in temperature.
4. Aquatic animals are more comfortable in cold water because as the temperature is less the solubility of dissolved oxygen ………
5. Hydrated salts contain ……… of crystallization.
6. He-O₂ mixture is a binary solution of …….. in ………. solution.
7. The solvent used for dissolving Sulphur is ……….
8. The solubility of NaOH at 25°C is ……….
9. According to Henry’s Law, the solubility of a gas in liquid is ………. proportional to the pressure of the gas over the solution at definite temperature.
10. Anhydrous Calcium chloride is a ………. substance.
11. ……… substances absorb enough water from the atmosphere and get completely dissolved.
12. When 90g of sodium bromide is dissolved in 100 g of water at 25°C it forms a ………. solution.
13. ………. is an example of a binary solution with liquid in Gas.
14. Air and sea water are important ……… solution.
15. A quaternary solution contains ……….. components.
16. The primary factor which determines the characteristic of a solution is ………..
Answer:
1. Homogeneous
2. saturation
3. decreases
4. increases
5. water
6. Gas, Gas
7. CS₂ (or) Carbon disulphide
8. 80 g
9. directly
10. Hygroscopic
11. deliquescent
12. Unsaturated
13. Cloud
14. Homogeneous
15. four
16. Physical state

III. Match the following

Question 1.
Match the column I with column II.

Answer:
A. (iv)
B. (iii)
C. (v)
D. (ii)
E. (i)

Question 2.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (ii)
E. (i)

Question 3.
Match the column I with column II.

Answer:
A. (v)
B. (iii)
C. (ii)
D. (i)
E. (iv)

Question 4.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (i)
E. (ii)

Question 5.
Match the column I with column II.

Answer:
A. (iv)
B. (iii)
C. (i)
D. (v)
E. (ii)

IV. True or False: (If false give the correct statement)

1. In an aqueous solution of copper sulphate, the solvent is copper sulphate.
2. A solution containing sugar and salt in water is a binary solution.
3. An example of a solid solution is alloy.
4. The difference between concentrated and dilute solution can be observed by means of colour (or) density.
5. A saturated solution contains 91 g of Glucose in 100 g of water at 25°C.
6. Fat is dissolved in the aqueous solvent ether.
7. The solubility of a gas in a liquid is inversely proportional to the pressure of the gas at a definite temperature.
8. Mass percentage of a solution is expressed as .
9. The white vitriol is represented by the formula ZnSO₄ . 7H₂O.
10. Ferric chloride is a Hygroscopic substance.
Answer:
1. False – In an aqueous solution of copper sulphate, the solvent is water.
2. False – A solution containing sugar and salt in water is a ternary solution.
3. True
4. True
5. True
6. False – Fat is dissolved in the non-aqueous solvent ether.
7. False – The solubility of a gas in a liquid is directly proportional to the pressure of the gas at a definite temperature.
8. True
9. True
10. False – Ferric chloride is a deliquescent substance.

V. Short answer questions:

Question 1.
(i) Which gas is dissolved in soft drinks?
(ii) What will you do to increase the solubility of this gas?
Answer:
(i) Carbon-di-oxide (CO₂) is dissolved in soft drinks.
(ii) An increase in pressure will increase the solubility of CO₂ gas.

Question 2.
Identify the type of binary solution given below.
Answer:

1. Alloys
2. Amalgam
3. Ethyl alcohol in water
4. Aerated drinks

Answer:

1. Solid in solid
2. liquid in solid
3. liquid in liquid
4. Gas in liquid

Question 3.
Explain why Nitrogen in soil is called a saturated solution in nature?
Answer:
Nitrogen in soil is an example of a saturated solution in nature. Soil cannot store more Nitrogen than it can hold.

Question 4.
Define Mass percentage.
Answer:
Mass percentage of a solution is defined as the percentage by mass of the solute present in the solution.

Question 5.
Define the term Molarity (M).
Answer:

Question 6.
Define the term Molality (m).
Answer:

Question 7.
Define the supersaturated solution.
Answer:
A supersaturated solution is one that contains more solute than the saturated solution at a given temperature.
E.g. 40 g of sodium chloride in 100 g of water at 25°C.

Question 8.
Justify the following statements with an explanation.
(i) Solubility of NH₄Cl increases with increase in temperature.
Answer:
Solubility of NH₄Cl increases with increase in temperature because it is an endothermic process.

(ii) Solubility of NaOH decreases with increase in temperature.
Answer:
Solubility of NaOH decreases with increase in temperature because it is an exothermic process.

Question 9.
Calculate the molarity of a solution containing 4 g of NaOH in 500 ml of water.
Answer:
Mass of NaOH = 4 g
Volume of solution = 500 ml

= 0.1 × 2
= 0.2 M

Question 10.
Calculate the molality of a solution containing 3 g of urea (molecular mass = 60) in 750 g of water.
Answer:
Mass of urea (solute) = 3 g
Mass of water (solvent) = 750 g
Formula:

Question 11.
Define dissolution.
Answer:
The process of uniform distribution of solute into solvent is called dissolution.

VI. Long answer questions:

Question 1.
Answer the blanks given in the table.
Answer:

Question 2.
Write a note on the type of solution based on the type of solvent.
Answer:
(i) Aqueous solution : The solution in which water acts as a solvent is called aqueous solution. In general, ionic compounds are soluble in water and form aqueous solutions more readily than covalent compounds.
Eg: Common salt in water, Sugar in water, Copper sulphate in water etc..

(ii) Non-Aqueous solution : The solution in which any liquid, otter than water, acts as a solvent is called non-aqueous solution. Solvent other than water is referred to as non-aqueous solvent. Generally, alcohols, benzene, ethers, carbon disulphide, acetone, etc., are used as non- aqueous solvents.
Eg: Sulphur dissolved in carbon disulphide, Iodine dissolved in carbon tetrachloride.

Question 3.
Justify the following statements with an explanation.

1. The solubility of calcium oxide decreases with increase in temperature,
2. What happens to the solubility in the exothermic process with regard to temperature?
3. In the endothermic process, solubility increases with increase in temperature.
4. At a given temperature, an increase in pressure increases the solubility of the gas

Answer:

1. In an exothermic process, the solubility decreases. When calcium oxide dissolves in water, an exothermic reaction takes place, and so the solubility of calcium oxide decreases
2. In an exothermic process, the solubility decreases with the increase in temperature, as there is already an evolution of heat and it is observed.
3. In an endothermic process, the solubility increases. The solubility of KNO₃ in water is an endothermic reaction and so solubility increases with the increase of temperature.
4. At a given temperature, an increase in pressure increases the solubility of gas according to Henry’s law. e.g. (CO₂ in soft drinks)

VII. Hot Questions.

Question 1.
50 ml tincture of benzoin, antiseptic solution contains 10 ml of benzoin. Calculate the volume of percentage of benzoin.
Answer:
Volume of the solute, Benzoin = 10 ml
Volume of the solution, tincture of benzoin = 50 ml

= 20% (v/v)

Question 2.
Neomycin, the antibiotic cream contains 300 mg of neomycin sulphate the active ingredient in 30 g of ointment base. Calculate the mass percentage of neomycin.
Answer:
Mass of neomycin sulphate(solute) = 300 mg
Mass of the ointment (solution) = 30 g
Formula:

VIII. Numerical problems:

Question 1.
Calculate the molality of the solution containing 18 g of Glucose (Molecular mass 180) in 2 kg of water.
Answer:
Mass of Glucose = 18 g
Molecular mass of Glucose = 180

= 0. 05 m

Question 2.
Calculate the molarity of a solution containing 5.85 g of sodium chloride in 500 ml of the water. (Molecular mass = 58.5)
Answer:
Mass of the solute = 5.85 g
Volume of the solution = 500
No. of moles of NaCl = \(\frac{5.85}{58.5}\) = 0.1

= \(\frac{0.1}{500}\) × 1000 = 0.2 M

Students can download 10th Science Chapter 8 Periodic Classification of Elements Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 8 Periodic Classification of Elements

Samacheer Kalvi 10th Science Periodic Classification of Elements Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
The number of periods and groups in the periodic table are:
(a) 6, 16
(b) 7, 17
(c) 8, 18
(d) 7, 18
Answer:
(d) 7, 18

Question 2.
The basis of modem periodic law is ____.
(a) atomic number
(b) atomic mass
(c) isotopic mass
(d) number of neutrons.
Answer:
(a) atomic number

Question 3.
……….. group contains the member of the halogen family.
(a) 17th
(b) 15th
(c) 18th
(d) 16th
Answer:
(a) 17th

Question 4.
_______ is a relative periodic property.
(a) atomic radii
(b) ionic radii
(c) electron affinity
(d) electronegativity.
Answer:
(b) ionic radii

Question 5.
Chemical formula of rust is:
(a) Fe0.xH₂O
(b) Fe04.xH₂O
(c) Fe₂O₃. xH₂O
(d) FeO
Answer:
(c) Fe₂O₃. xH₂O

Question 6.
In the aluminothermic process the role of Al is:
(a) oxidizing agent
(b) reducing agent
(c) hydrogenating agent
(d) sulphurising agent
Answer:
(b) reducing agent

Question 7.
The process of coating the surface of the metal with a thin layer of zinc is called ____.
(a) painting
(b) thinning
(c) galvanization
(d) electroplating.
Answer:
(c) galvanization

Question 8.
Which of the following inert gas has electrons in the outermost shell?
(a) He
(b) Ne
(c) Ar
(d) Kr
Answer:
(a) He

Question 9.
Neon shows zero electron affinity due to ____.
(a) stable arrangement of neutrons
(b) stable configuration of electrons
(c) reduced size
(d) increased density.
Answer:
(b) stable configuration of electrons

Question 10.
……….. is an important metal to form amalgam.
(a) Ag
(b) Hg
(c) Mg
(d) Al
Answer:
(b) Hg

II. Fill in the blanks:

1. If the electronegativity difference between two bonded atoms in a molecule is greater than 1.7, the nature of bonding is ………..
2. …………. is the longest period in the periodical table.
3. ………… forms the basis of modern periodic table.
4. If the distance between two Cl atoms in Cl₂ molecule is 1.98 Å, then the radius of Cl atom is ………..
5. Among the given species A^– A⁺, and A, the smallest one in size is ……….
6. The scientist who propounded the modern periodic law is …………
7. Across the period, ionic radii ………… (increases,decreases).
8. ……….. and ………… are called inner transition elements.
9. The chief ore of Aluminium is ………….
10. The chemical name of rust is ………….
Answer:
1. ionic
2. 6th (sixth) period
3. Atomic number
4. 0.99 Å
5. A⁺
6. Dimitri Mendeleev
7. decreases
8. Lanthanides, Actinides
9. bauxite
10. hydrated ferric oxide

III. Match the following:

Answer:
A. (ii)
B. (v)
C. (iv)
D. (iii)
E. (i)

IV. True or False: (If false give the correct statement)

1. Moseley’s periodic table is based on atomic mass.
2. Ionic radius increases across the period from left to right.
3. All ores are minerals; but all minerals cannot be called as ores.
4. Aluminium wires are used as electric cables due to their silvery white colour.
5. An alloy is a heterogenous mixture of metals.
Answer:
1. False – Moseley’s periodic table is based on atomic number.
2. True
3. True
4. False – Aluminium wires are used as electric cables because it is a good conductor of heat and electricity.
5. False – An alloy is an homogeneous mixture of metals.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: The nature of bond in HF molecule is ionic.
Reason: The electronegativity difference between H and F is 1.9.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: Magnesium is used to protect steel from rusting.
Reason: Magnesium is more reactive than iron.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: An uncleaned copper vessel is covered with greenish layer. Reason: copper is not attacked by alkali.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

VI. Short answer questions:

Question 1.
A is a reddish brown metal, which combines with O₂ at < 1370 K gives B, a black coloured compound. At a temperature > 1370 K, A gives C which is red in colour. Find A, B and C with reaction.
Answer:
(A) is a reddish brown metal – Copper

A – Copper; B – Cupric oxide; C – Cuprous oxide.

Question 2.
A is a silvery white metal. A combines with O₂ to form B at 800°C, the alloy of A is used in making the aircraft. Find A and B.
Answer:
A – Silvery white metal – Aluminium

The alloys of aluminium, Duralumin and Magnalium are used in making the aircraft.
A – Aluminium; B – Aluminium oxide.

Question 3.
What is rust? Give the equation for the formation of rust.
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated ferric oxide on its surface. This compound is known as rust and the phenomenon of formation of rust is known as rusting.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 4.
State two conditions necessary for rusting of iron.
Answer:
(i) The presence of water and oxygen is essential for the rusting of iron.
(ii) Impurities in the iron, the presence of water vapour, acids, salts and CO₂ speeds up rusting.

VII. Long answer questions:

Question 1.
(a) State the reason for addition of caustic alkali to bauxite ore during purification of bauxite.
Answer:
Caustic alkali is added to bauxite, to dissolve bauxite ore and obtain a solution of sodium aluminate.

(b) Along with cryolite and alumina, another substance is added to the electrolyte mixture. Name the substance and give one reason for the addition.
Answer:
CaF₂ (Fluorspar) is added along with cryolite and alumina. It is added to reduce the high melting point of the electrolyte.

Question 2.
The electronic configuration of metal A is 2, 8, 18, 1.
The metal A when exposed to air and moisture forms B a green layered compound. A with con. H₂SO₄ forms C and D along with water. D is a gaseous compound. Find A, B, C and D.
Answer:
Metal (A) with electronic configuration- 2, 8, 18, 1 is copper.
2Cu + O₂ + CO₂ + H₂O → CuCO₃. Cu(OH)₂ (B)
Copper carbonate (Green layer)

(A) – Copper (Cu)
(B) – Copper Carbonate (CuCO₃. Cu(OH)₂)
(C) – Copper Sulphate (CuSO₄)
(D) – Sulphur dioxide (SO₂)

Question 3.
Explain the smelting process.
Answer:
The roasted ore of copper is mixed with powdered coke and sand and is heated in a blast furnace to obtain matte (Cu₂S + FeS) and slag. The slag is removed as waste.
2 FeS + 3O₂ → 2 FeO + 2 SO₂
2 Cu₂S + 3O₂ → 2 Cu₂O + 2SO₂
Cu₂O + FeS → Cu₂S + FeO
FeO + SiO₂ → FeSiO₂ (slag)

VIII. HOT questions:

Question 1.
Metal A belongs to period 3 and group 13. A in red hot condition reacts with steam to form B. A with strong alkali forms C. Find A, B and C with reactions.
Answer:
Metal A belongs to Period 3 and Group 13. So metal ‘A’ is aluminium.
(A) in red hot condition reacts with steam to form ‘B’.

‘A’ with strong alkali forms ‘C’

(A) – Aluminium
(B) – Aluminium oxide
(C) – Sodium meta aluminate

Question 2.
Name the acid that renders aluminium passive. Why?
Answer:
Dilute or concentrated nitric acid (HNO₃) renders aluminium passive. Because nitric acid does not attack aluminium but it renders aluminium passive due to the formation of an oxide film on its surface.

Question 3.
(a) Identify the bond between H and F in HF molecule.
Answer:
Ionic, because the electronegativity difference is more than 1.7.

(b) What property forms the basis of identification?
Answer:
Electronegativity.

(c) How does the property vary in periods and in groups?
Answer:
In a period, from left to right the electronegativity increases because of the increase in the nuclear charge.
In a Group, from top to bottom, the electronegativity decreases because of the increase in size of the elements.

Samacheer Kalvi 10th Science Periodic Classification of Elements Additional Important Questions and Answers

I. Choose the correct answer:

Question 1.
The shortest period in the periodic table contains elements.
(a) 18
(b) 8
(c) 2
(d) 32
Answer:
(c) 2

Question 2.
Group number of carbon family is _____.
(a) 13
(b) 15
(c) 17
(d) 14.
Answer:
(d) 14.

Question 3.
The ore forming elements, chalcogens are present in ……… group of the modern periodic table.
(a) 18th
(b) 1st
(c) 2nd
(d) 16th
Answer:
(d) 16th

Question 4.
Valency of all the alkali metals is _____.
(a) 1
(b) 2
(c) 3
(d) 4.
Answer:
(a) 1

Question 5.
The largest atom in the 2nd period of the periodic table is:
(a) Li
(b) Be
(c) F
(d) Ne
Answer:
(a) Li

Question 6.
The covalent radii of Hydrogen, if the distance between the Hydrogen nuclei of the molecule is 0.74 Å is:
(a) 1.58 Å
(b) \(\frac{0.74}{4}\) Å
(c) 0.37 Å
(d) 0.74 Å
Answer:
(c) 0.37 Å

Question 7.
Pick out the correct ionic radii in increasing order for the following species – Na, Cl, Na⁺, Cl^– _____.
(a) Na > Cl > Na⁺ > Cl^–
(b) Cl > Na > Na⁺ > Cl^–
(c) Cl^– > Na > Na⁺ > Cl
(d) Cl < Na⁺ < Cl^– < Na.
Answer:
(d) Cl < Na⁺ < Cl^– < Na.
Hint:
Na = 186 pm,
Cl = 91 pm,
Na⁺ = 116 pm,
Cl^– = 167 pm.

Question 8.
In the third period, the first ionization potential is of the order:
(a) Na > Al > Mg > Si > P
(b) Mg > Na > Si > P > Al
(c) Na < Al < Mg < Si < P
(d) Na < Al < Mg < Si < P
Answer:
(c) Na < Al < Mg < Si < P

Question 9.
Which one of the following is the least electronegative element?
(a) Bromine
(b) Chlorine
(c) Iodine
(d) Hydrogen
Answer:
(d) Hydrogen

Question 10.
Which is a widely used a scale to determine the electronegativity?
(a) Pauling scale
(b) Moseley scale
(c) Mendeleev scale
(d) none of these.
Answer:
(a) Pauling scale

Question 11.
Which one of the following orders of ionic radii is correct?
(a) H^– > H⁺ > H
(b) Na⁺ > F^– > O^2-
(c) F > O^2- > Na⁺
(d) None of these
Answer:
(d) None of these

Question 12.
The percentage of carbon in Pig iron is:
(a) < 0.25%
(b) 0.25 – 2%
(c) 2 – 4.5%
(d) > 5%
Answer:
(c) 2 – 4.5%

Question 13.
The chemical formula of clay is _____.
(a) Al₂O₃
(b) Al₂O₃.2H₂O
(c) Al₂O₃. 2SiO₂.2H₂O
(d) Al₂O₃. 2SiO₂.H₂O.
Answer:
(c) Al₂O₃. 2SiO₂.2H₂O

Question 14.
The temperature in the combustion zone is maintained at:
(a) 1500°C
(b) 400°C
(c) 1000°C
(d) 1380°C
Answer:
(a) 1500°C

Question 15.
Oil used in Froth floatation method is _____.
(a) pine oil
(b) natural oil
(c) crude oil
(d) Synthetic oil.
Answer:
(a) pine oil

Question 16.
The first most abundant metal present in the Earth crust is:
(a) Iron
(b) Aluminium
(c) Zinc
(d) Copper
Answer:
(b) Aluminium

Question 17.
……….. metal is used for making calorimeters.
(a) Copper
(b) Tin
(c) Mercury
(d) Iron
Answer:
(a) Copper

Question 18.
More reactive metal is _____.
(a) Zn
(b) Fe
(c) Ag
(d) Na.
Answer:
(d) Na.

Question 19.
The chief ore of Iron is:
(a) Magnesite
(b) Galena
(c) Cinnabar
(d) Haematite
Answer:
(d) Haematite

Question 20.
The metal which melts at room temperature is:
(a) Zinc
(b) Lead
(c) Gallium
(d) Tin
Answer:
(c) Gallium

Question 21.
Conversion of bauxite into alumina is _____.
(a) Hall’s process
(b) Alumino thermic process
(c) Baeyer’s process
(d) Bessemerisation process.
Answer:
(c) Baeyer’s process

Question 22.
………. metal can be cut with knife.
(a) Potassium
(b) Gallium
(c) Mercury
(d) Gold
Answer:
(a) Potassium

Question 23.
………. is not a good conductor of heat and electricity.
(a) Silver
(b) Tungsten
(c) Copper
(d) Aluminium
Answer:
(b) Tungsten

Question 24.
Electrolyte used in Hall’s process ______.
(a) Pure alumina + molten cryolite + fluorspar
(b) Pure alumina + molten bauxite + fluorspar
(c) Pure bauxite + molten cryolite + fluorspar
(d) Pure bauxite + molten Haematite + fluorspar.
Answer:
(a) Pure alumina + molten cryolite + fluorspar

Question 25.
The foaming agent used for froth floatation process is:
(a) Coconut oil
(b) Pine oil
(c) Sodium chloride
(d) Groundnut oil
Answer:
(b) Pine oil

Question 26.
Three elements A, B and C are having the electronic configuration Is² 2s¹, Is² 2s² and Is² 2s² 2p¹ respectively. Which element will have the lowest ionization energy?
(a) A
(b) B
(c) C
(d) B and C
Answer:
(a) A

Question 27.
Metal used in household utensils is ______.
(a) Al
(b) Co
(c) Fe
(d) Na.
Answer:
(a) Al

Question 28.
Which one of the following pair is a metalloid?
(a) Na and K
(b) F and Cl
(c) Cu and Hg
(d) Si and Ge
Answer:
(d) Si and Ge

Question 29.
The highly metallic element will have the configuration of:
(a) 2, 8, 7
(b) 2, 8, 8, 5
(c) 2, 8, 8, 1
(d) 2, 8, 2
Answer:
(c) 2, 8, 8, 1

Question 30.
The metal used in electroplating is ______.
(a) Cu
(b) Al
(c) Fe
(d) Co.
Answer:
(a) Cu

Question 31.
The flux which is used when the gangue present in the ore is acidic:
(a) Silica
(b) Calcium oxide
(c) Calcium silicate
(d) Cuprous sulphide
Answer:
(b) Calcium oxide

Question 32.
Matte is a mixture of:
(a) Cu₂O + Cu₂S
(b) Cu₂O + FeS
(c) Cu₂S + FeS
(d) Cu₂O + PbS
Answer:
(c) Cu₂S + FeS

Question 33.
Fe reacts with dilute nitric acid in cold condition to give ______.
(a) Ferrous nitride
(b) Ferrous nitrate
(c) Ferric nitride
(d) Ferric nitrate.
Answer:
(b) Ferrous nitrate

Question 34.
In the brass alloy, which is solvent?
(a) Zn
(b) Co
(c) Ag
(d) Cu.
Answer:
(d) Cu.

II. Fill in the blanks:

1. The major component of the matte is ………….
2. The modern periodic table is based on ………..
3. The valency of alkali metals is …………
4. The unreactive elements are present in group ………..
5. In the 2nd period, the smallest atom is ……….
6. The size of a cation is ………… than the neutral atom.
7. ……….. is the unit of ionization energy.
8. The ionization energy ……… down the group in the periodic table.
9. The electron affinities of noble gases are …………
10. ………. is the process of extracting the ore from the Earth’s crust.
11. Galena is the ore of …………..
12. The silvery white metal which is a good conductor of heat and electricity is …………
13. The slag formed during Bessemerisation process is ………….
14. Blister copper contains ………. percentage of copper.
15. Haematite ore is concentrated by ……….. washing.
Answer:
1. Cu₂S
2. atomic number
3. one
4. 18
5. Neon
6. smaller
7. KJ/mol
8. decreases
9. zero
10. Mining
11. lead
12. aluminium
13. Iron silicate or FeSiO₃
14. 98%
15. hydraulic

III. Match the following:

Question 1.
Match the column I with column II.

Answer:
A. (iv)
B. (v)
C. (i)
D. (ii)
E. (iii)

Question 2.
Match the column I with column II.

Answer:
A. (ii)
B. (iv)
C. (v)
D. (iii)
E. (i)

Question 3.
Match the column I with column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (i)
E. (ii)

Question 4.
Match the column I with column II.

Answer:
A. (v)
B. (iv)
C. (ii)
D. (iii)
E. (i)

IV. True or false. (If false give the correct statement)

1. Alkali metals are generally extracted by the electrolysis of their ores in fused state.
2. Every mineral is an ore but every ore is not a mineral.
3. Slag is a product formed during smelting by combination of flux and impurities.
4. Reactive metals occur in native state.
5. Malachite is a sulphide ore of copper.
6. Lanthanides are present in the 6th group of the periodic table.
7. Atomic radius increases as we go across the period due to increase in size.
8. As the positive charge increases, the size of the cation decreases.
9. If the difference in electronegativity is greater than 1.7, the bond is considered to be covalent.
10. Siderite is the carbonate ore of calcium.
Answer:
1.True
2. True
3. True
4. False – Reactive metals always occur in the combined state.
5. False – Malachite is the carbonate ore of copper.
6. False – Lanthanides are present in the 6th period of the periodic table.
7. False – Atomic radius increases as we go across the period due to decrease in size.
8. True
9. False – If the difference in electronegativity is greater than 1.7, the bond is considered to be ionic.
10. False – Siderite is the carbonate ore of Iron.

V. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: Zinc blende is concentrated by Froth floatation process.
Reason: Zinc blende is a sulphide ore.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: In thermite welding, aluminium powder and Fe₂O₃ are used.
Reason: Aluminium powder is a strong reducing agent.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 3.
Assertion: To design the body of an aircraft, aluminium alloys are used.
Reason: Aluminium becomes passive when it is treated with dil or con.HNO₃
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

Question 4.
Assertion: Tinstone and the impurity wolframite are seperated by magnetic separation.
Reason: Tinstone is magnetic and wolframite is non-magnetic in nature.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 5.
Assertion: Bauxite is purified by leaching.
Reason: Bauxite undergoes thermal decomposition.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(b) Assertion is correct, Reason is wrong.

VI. Short answer questions:

Question 1.
State the modern periodic law.
Answer:
The physical and chemical properties of the elements are the periodic function of their atomic number.

Question 2.
‘X’ is a silvery white metal. X reacts with O₂ to form Y. The same compound is obtained from the metal on reaction with steam with the liberation of hydrogen gas. Identify X and Y.
Answer:
(i) Silvery white metal ‘X’ is Aluminium.
(ii) It reacts with O₂ to form ‘Y’

(iii) Y can also be obtained on reaction with steam with the liberation of H₂.

Question 3.
Write any four characteristics of periods.
Answer:

• In a period, the electrons are filled in the same valence shell of all elements.
• As the electronic configuration changes along the period, the chemical properties of the elements also change.
• The atomic size of the elements in a period decreases from left to right
• In a period, die metallic character of the element decreases, while their non-metallic character increases.

Question 4.
Write the Principle of Hydraulic washing.
Answer:
The difference in the densities or specific gravities of the ore and the gangue is the main principle behind this method.

Question 5.
What are coinage metals?
Answer:
Copper, silver and gold are called coinage metals, as they are used in making coins and jewellery.

Question 6.
How will you separate tinstone from wolframite?
Answer:
Magnetic separation method. Tinstone is magnetic in nature.
Method: The crushed ore is placed over a conveyer belt which rotates around two metal wheels, one of which is magnetic. The magnetic particles are attracted to the magnetic wheel and fall separately apart from the non¬magnetic particles.

Question 7.
What are ores?
Answer:
The mineral from which a metal can be readily and economically extracted on a large scale is said to be ore.
eg. Bauxite Al₂O₃.2H₂O is the ore of Aluminium

Question 8.
Define electronegativity.
Answer:
It is the tendency of an element in a covalent bond to attract the shared pair of electrons towards itself. It is a relative property.

Question 9.
In what period and group will an element with z = 118 will be present?
Answer:
Elements with z = 118 will be present in Period number ‘7’ and Group number 18.

Question 10.
Why flux is added during metallurgy?
Answer:
Flux is the substance added to the ore to reduce the fusion temperature and to remove impurities.
e.g. CaO, SiO₂

Question 11.
State the trends in the electronegativity in a Group and period.
Answer:
In a Group: Electronegativity decreases in a group because of the increased number of energy levels.
In a Period: The electronegativity increases because the increase in the nuclear charge.

Question 12.
Write a note about smelting.
Answer:
Smelting is a process of reducing the roasted metallic oxide to metal in a molten condition. In this process, impurities are removed by the addition of flux as slag.

Question 13.
Write the formula of the ores of Aluminium.
Answer:

Question 14.
Explain the action of Aluminium with air.
Answer:
On heating at 800°C, aluminium bums in the air very brightly forming its oxide and nitride.
4Al + 3O₂ → 2Al₂O₃ (Aluminium oxide)
2Al + N₂ → 2AlN (Aluminium nitride).

Question 15.
What happen when Aluminium reacts with steam?
Answer:
When steam is passed over red hot aluminium, H₂ gas is evolved.

Question 16.
Write the reaction of Aluminium with Sodium hydroxide?
Answer:

Question 17.
Explain the electrolytic refining of copper.
Answer:
Cathode: A thin plate of pure copper metal.
Anode: A block of impure copper metal.
Electrolyte: Copper sulphate solution + dilute H₂SO₄
When an electric current is passed through the electrolytic solution, pure copper gets deposited at the cathode and the impurities are settled at the bottom of the anode as anode mud.

Question 18.
Mention the uses of Aluminium.
Answer:
Aluminium is used in

1. household utensils
2. electrical cable industry
3. making aeroplanes and other industrial machine parts.

Question 19.
What are the methods employed to make an alloy?
Answer:

1. By fusing the metals together. Eg: Brass is made by melting zinc and copper.
2. By compressing finely divided metals. Eg: wood mexai.

Question 20.
Write the components of wood metal.
Answer:
Wood metal is an alloy of Lead, Tin, Bismuth and Cadmium.

Question 21.
What are the uses of copper?
Answer:

• Copper is used in manufacturing electric cables and other electric appliances.
• Copper is used for making utensils, containers, calorimeters and coins.
• Copper is used in electroplating.
• Copper is alloyed with gold and silver for making coins and jewels.

Question 22.
Give example for non-ferrous copper and aluminium alloys. Non-ferrous copper alloys: Brass (Cu, Zn), Bronze (Cu, Sn)
Answer:
Non-ferrous aluminium alloys: Duralumin (Al, Mg, Cu, Mn), Magnalium (Al, Mg)

Question 23.
How is rust formed?
Answer:
When iron is exposed to moist air, it forms a layer of brown hydrated Ferric oxide on its surface. This compound is known as rust.
4Fe + 3O₂ + xH₂O → 2Fe₂O₃. xH₂O (Rust).

Question 24.
Why are the alloys prepared?
Answer:

1. To modify appearance and colour.
2. To modify chemical activity.
3. To lower the melting point.
4. To increase hardness and tensile strength.
5. To increase resistance to electricity.

Question 25.
Define corrosion.
Answer:
Corrosion is the gradual destruction of metals by chemical or electrochemical reaction with the environment.

Question 26.
What are alloys? How are they prepared?
Answer:

• An alloy is a homogeneous mixture of a metal with other metals or with non-metals that are fused together. e.g. Brass is an alloy of zinc (solute) in copper (solvent)
• Alloys are prepared by fusing the metals together.
• Alloys are prepared by compressing finely divided metals one over the other.

Question 27.
Which is known as Wet corrosion or Electrochemical corrosion?
Answer:
The corrosive action in the presence of moisture is called wet corrosion. It occurs as a result of electrochemical reaction of metal with water or aqueous solution of salt or acids or bases.

Question 28.
Write a note on Cathodic protection.
Answer:
It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called Sacrificial metal to act as anode ensuring cathodic protection.

Question 29.
What are the methods used to prevent corrosion?
Answer:
Corrosion of metals is prevented

• by coating with paints
• by coating with oil and grease
• by alloying with other metals
• by the process of galvanization
• by electroplating
• by sacrificial protection

Question 30.
A reddish brown metal ‘A’ reacts with dil.HCl in the presence of O₂ and forms the compound ‘B’. ‘B’ can also be prepared by heating the metal A with Cl₂. Identify A and B.
Answer:
Reddish brown metal ‘A’ is copper.
(A) reacts with dil.HCl in the presence of O₂ and forms CuCl₂ which is ‘B’.

(B) can also prepared by the action of Cl₂.

Question 31.
Write the uses of copper.
Answer:

1. It is extensively used in manufacturing electric cables and other electric appliances.
2. It is used for making utensils, containers, calorimeters and coins.
3. It is used in electroplating.
4. It is alloyed with gold and silver for making coins and jewels.

Question 32.
Write the name and formula of the ores of iron.
Answer:

Question 33.
Define periodicity.
Answer:
The electronic configurations of elements help us to explain the periodic recurrence of physical and chemical properties. Anything which repeats itself after a regular interval is called periodic and this behaviour is called periodicity.

Question 34.
What happens in the combustion zone during the extraction of iron.
Answer:
The temperature in the combustion zone is 150°C. In this region coke bums 02 to form CO₂, when the charge comes in contact with a hot blast of air.

Question 35.
Explain the reactions taking place in the reduction zone.
Answer:
In the upper region of reduction zone, the temperature is at 400°C. In this region CO reduces ferric oxide to form spongy iron.

Question 36.
Define Metallic radius.
Answer:
It is defined as half the distance between the nuclei of adjacent metal atoms.

Question 37.
Complete the following reactions.

1. 4Fe + 10HNO₃ → 4Fe(NO₃)₂ + ………. + 3H₂O
2. 2Fe + 6H₂SO₄ → Fe₂(SO₄)₃ + ………. + 6H₂O

Answer:

1. NH₄NO₃
2. 3SO₂

Question 38.
What happens when steam is passed over red hot iron?
Answer:
When steam is passed over red hot iron magnetic oxide is formed.
3Fe + 4H₂O (steam) → Fe₃O₄ + 4H₂↑

Question 39.
Define Electron affinity.
Answer:
Electron affinity is the amount of energy released when a gaseous atom gains an electron to form its anion. It is also measured in kJ / mol.

Question 40.
Complete the table.
Answer:

Question 41.
Define Metallurgy.
Answer:
Metallurgy is a science of extracting metals from their ores and modifying the metals into alloys for various uses, based on their physical and chemical properties and their structural arrangement of atoms.

Question 42.
Write a short note on leaching or chemical process.
Answer:
This method is employed when the ore is in a very pure form. The ore is treated with a suitable reagent such that the ore is soluble in it but the impurities are not. The impurities are removed by filtration. The solution of the ore, ie., the filtrate is treated with a suitable reagent which precipitates the ore.
E.g. Bauxite Al₂O₃.2H₂O, the ore of aluminium.

Question 43.
Relate all the four columns of the table with their unique properties.
Answer:

Question 44.
Guess Who I am?
(i) I am preserved in Kerosene.
Answer:
Sodium

(ii) My ore is leached with NaOH.
Answer:
Aluminium

(iii) I sacrifice myself to protect my friend Iron.
Answer:
Magnesium

(iv) I am being used in propellers
Answer:
Nickel steel

Question 45.
Explain the method of making alloys.
Answer:

• By fusing the metals together. E.g. Brass is made by melting zinc and copper.
• By compressing finely divided metals. E.g. Wood metal: an alloy of lead, tin, bismuth and cadmium powder is a fusible alloy.

Question 46.
Write the differences between a mineral and a ore.
Answer:

VII. Long answer questions:

Question 1.
Write the reactions taking place during Bessemerisation of copper.
Answer:
2 FeS + 3O₂ → 2FeO + 2SO₂↑

2Cu₂S + 3O₂ → 2 Cu₂O + 2 SO₂↑
2Cu₂O + Cu₂S → 6 Cu + SO₂↑

Question 2.
How do electronegativity values help to find out the nature of bonding between atoms?
Answer:

• If the difference in electronegativity between two elements is 1.7, the bond has 50% ionic character and 50 % covalent character.
• If the difference is less than 1.7, the bond is considered to be covalent.
• If the difference is greater than 1.7, the bond is considered to be ionic.

Question 3.
Explain Froth floatation with diagram.
Answer:
Principle: This process depends on the preferential wettability of the ore with oil (pine oil) and the gangue particles by water. Lighter ores, such as sulphide ores, are concentrated by this method. Eg: Zinc blende (ZnS).

Question 4.
Explain the Baeyer’s process of conversion of Bauxite into alumina.
Answer:
(i) Bauxite ore is finely ground and heated under pressure with a solution of concentrated caustic soda solution at 150°C to obtain sodium meta aluminate.
(ii) On diluting sodium meta aluminate with water, a precipitate of aluminium hydroxide is formed.
(iii) The precipitate is filtered, washed, dried and ignited at 1000°C to get alumina.

Question 5.
Explain the Hall’s Process of electrolytic reduction of alumina with diagram.
Answer:
Hall’s Process:
Aluminium is produced by the electrolytic reduction of fused alumina (Al₂O₃) in the electrolytic cell.
Cathode : Iron tank linked with graphite
Anode : A bunch of graphite rods suspended in molten electrolyte.
Electrolyte : Pure alumina + molten cryolite + fluorspar (fluorspar lowers the fusion temperature of electrolyte)

Temperature: 900 – 950 °C
Voltage used: 5 – 6 V
Overall reaction: 2 Al₂O₃ → 4 Al + 3O₂↑

Question 6.
Write the reaction involved in the middle region of blast furnace during the extraction of iron.
Answer:
The Middle Region (Fusion Zone): The temperature prevails at 1000°C. In this region, CO₂ is reduced to CO.

Limestone decomposes to calcium oxide and CO₂.

These two reactions are endothermic due to absorption of heat. Calcium oxide combines with silica to form calcium silicate slag.
CaO + SiO₂ → CaSiO₃

Question 7.
What are the three different types of iron? Write their uses.
Answer:
(i) Pig iron (Iron with 2-4.5% of carbon): It is used in making pipes, stoves, radiators, railings, manhole covers and drain pipes.
(ii) Steel (Iron with < 0.25% of carbon): It is used in the construction of buildings, machinery, transmission cables and T. V towers and in making alloys.
(iii) Wrought iron (Iron with 0.25-2% of wraught carbon): It is used in making springs, anchors and electromagnets.

Question 8.
What is corrosion? Write the chemistry behind the formation of rust.
Answer:
(i) The slow and steady destruction of a metal by chemical or electro chemical reaction with the environment.
(ii) When the surface of iron is exposed to moisture and other gases present in the atmosphere, the following chemical reaction takes place.
Fe → Fe²⁺ + 2e^–
O₂ + 2H₂O + 4e^– → 4OH^–
O₂ + 4H⁺ + 4e^– → 2H₂O
The Fe²⁺ ions are oxidised to Fe³⁺ ions.
The Fe³⁺ ions combine OH^– ions to form Fe(OH)₃. This becomes rust which is hydrated ferric oxide with the formula Fe₂O₃.xH₂O. It is a reddish brown substance.

Question 9.
Explain the methods of preventing corrosion.
Answer:
(i) Alloying : The metals can be alloyed to prevent the process of corrosion. Eg: Stainless Steel

(ii) Surface Coating : It involves application of a protective coating over the metal. It is of the following types:
(a) Galvanization: It is the process of coating zinc on iron sheets by using electric current.
(b) Electroplating: It is a method of coating one metal over another metal by passing electric current.
(c) Anodizing: It is an electrochemical process that converts the metal surface into a decorative, durable and corrosion resistant. Aluminium is widely used for anodizing process.
(d) Cathodic Protection: It is the method of controlling corrosion of a metal surface protected is coated with the metal which is easily corrodible. The easily corrodible metal is called sacrificial metal to act as anode ensuring cathodic protection.

Question 10.
Discuss the main featured of Periods in the modern periodic table (or) long form of periodic table.
Answer:
The horizontal rows are called periods.There are seven periods in the periodic table.

1. First period (Atomic number 1 and 2): This is the shortest period. It contains only two elements (Hydrogen and Helium).
2. Second period (Atomic number 3 to 10): This is a short period. It contains eight elements (Lithium to Neon).
3. Third period (Atomic number 11 to 18): This is also a short period. It contains eight elements (Sodium to Argon).
4. Fourth period (Atomic number 19 to 36): This is a long period. It contains eighteen elements (Potassium to Krypton). This includes 8 normal elements and 10 transition elements.
5. Fifth period (Atomic number 37 to 54): This is also a long period. It contains 18 elements (Rubidium to Xenon). This includes 8 normal elements and 10 transition elements.
6. Sixth period (Atomic number 55 to 86): This is the longest period. It contains 32 elements (Caesium to Radon). This includes 8 normal elements, 10 transition elements and 14 inner transition elements (Lanthanides).
7. Seventh period (Atomic number 87 to 118): Like the sixth period, this period also accommodates 32 elements. Recently 4 elements have been included by IUPAC.

Question 11.
Discuss the main feature of Groups in the long form of periodic table.
Answer:
(i) The vertical columns in the periodic table starting from top to bottom are called groups. There are 18 groups in the periodic table.

(ii) Based on the common characteristics of elements in each group, they can be grouped as various families.

(iii) The Lanthanides and Actinides, which form part of Group 3 are called inner transition elements.

(iv) Except ‘group O’, all the elements present in each group have the same number of electrons in their valence shell and thus have the same valency. Eg: all the elements of group 1 have one electron in their valence shells (Is¹). So, the valency of all the alkali metals is ‘ 1’.

(v) As the elements present in a group have identical valence shell electronic configurations, they possess similar chemical properties.

(vi) The physical properties of the elements in a group such as melting point, boiling point and density vary gradually.

(vii) The atoms of the ‘group 0’ elements have stable electronic configuration in their valence shells and hence they are unreactive.

VIII. Hot Questions:

Question 1.
Why noble gases have zero electron affinity value?
Answer:
Noble gases show no tendency to accept electrons because the outers and p orbitals of noble gases are completely filled. No more electrons can be added to them and hence their electron affinities are zero.

Question 2.
Arrange the following ions in order of their increasing ionic radii.
Answer:
Li⁺, Mg²⁺, K⁺ Al³⁺
Al³⁺ < Li⁺ < Mg²⁺ < K⁺

Question 3.
Cationic radius is smaller than its corresponding neutral atom. Why?
Answer:
When a neutral atom lose one or more electrons it forms a cation.
Na → Na⁺ + e^–
The radius of this cation (r_Na+)is decreased than its parent atom (r_Na).
When an atom is charged to cation, the number of nuclear charges becomes greater than the number of orbital electrons. Florence the remaining electrons are more strongly attracted by the nucleus. Hence the cationic radius is smaller than its corresponding neutral atom.

Students can download 10th Science Chapter 11 Carbon and its Compounds Questions and Answers, Notes, Samacheer Kalvi 10th Science Guide Pdf helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamilnadu Samacheer Kalvi 10th Science Solutions Chapter 11 Carbon and its Compounds

Samacheer Kalvi 10th Science Carbon and its Compounds Text Book Back Questions and Answers

I. Choose the best answer:

Question 1.
The molecular formula of an open-chain organic compound is C₃H₆. The class of the compound is:
(a) alkane
(b) alkene
(c) alkyne
(d) alcohol
Answer:
(b) alkene

Question 2.
The IUPAC name of an organic compound is 3-Methyl butan-1-ol. What type of compound it is?
(a) Aldehyde
(b) Carboxylic acid
(c) Ketone
(d) Alcohol
Answer:
(d) Alcohol

Question 3.
The secondary suffix used in IUPAC nomenclature of an aldehyde is:
(a) – ol
(b) – oic acid
(c) – al
(d) – one
Answer:
(c) – al

Question 4.
Which of the following pairs can be the successive members of a homologous series?
(a) C₃H₈ and C₄H₁₀
(b) C₂H₂ and C₂H₄
(c) CH₄ and C₃H₆
(d) C₂H₅OH and C₄H₈OH.
Answer:
(a) C₃H₈ and C₄H₁₀
Hint: Two successive members of a homologous series must have a difference of -CH₂ in the molecular formula.
\(\mathrm{C}_{3} \mathrm{H}_{8} \stackrel{+\mathrm{CH}_{2}}{\longrightarrow} \mathrm{C}_{4} \mathrm{H}_{10}\).

Question 5.
C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O is a:
(a) Reduction of ethanol
(b) Combustion of ethanol
(c) Oxidation of ethanoic acid
(d) Oxidation of ethanal
Answer:
(b) Combustion of ethanol

Question 6.
Rectified spirit is an aqueous solution which contains about ______ of ethanol.
(a) 95.5 %
(b) 75.5 %
(c) 55.5 %
(d) 45.5 %.
Answer:
(a) 95.5 %
Rectified spirit is a mixture of 95.5 % of ethanol and 4.5 % of water.

Question 7.
Which of the following are used as anaesthetics?
(a) Carboxylic acids
(b) Ethers
(c) Esters
(d) Aldehydes
Answer:
(b) Ethers

Question 8.
TFM in soaps represents _____ content in soap.
(a) mineral
(b) vitamin
(c) fatty acid
(d) carbohydrate.
Answer:
(c) fatty acid
Hint: TFM – Total Fatty Matter. It corresponds the fatty acid (oil).

Question 9.
Which of the following statements is wrong about detergents?
(a) It is a sodium salt of long chain fatty acids
(b) It is sodium salts of sulphonic acids
(c) The ionic part in a detergent is – SO₃ ^–Na⁺
(d) It is effective even in hard water.
Answer:
(a) It is a sodium salt of long-chain fatty acids

II. Fill in the blanks:

1. An atom or a group of atoms which is responsible for chemical characteristics of an organic compound is called …………
2. The general molecular formula of alkynes is ………..
3. In IUPAC name, the carbon skeleton of a compound is represented by ………. (root word / prefix / suffix)
4. (Saturated / Unsaturated) ……….. compounds decolourize bromine water.
5. Dehydration of ethanol by cone. Sulphuric acid forms ………. (ethene/ ethane)
6. 100 % pure ethanol is called ………..
7. Ethanoic acid turns ………… litmus to …………
8. The alkaline hydrolysis of fatty acids is termed as …………
9. Biodegradable detergents are made of …………. (branched / straight) chain hydrocarbons.
Answer:
1. Functional group
2- C_nH_2n-2
3. root word
4. unsaturated
5. ethene
6. absolute alcohol
7. Blue, red
8. Saponification
9. straight

III Match the following:

Question 1.
Match the Column I and Column II.

Answer:
A. (iii)
B. (iv)
C. (v)
D. (ii)
E. (i)

IV. Assertion and Reason:

Answer the following questions using the data given below:
Question 1.
Assertion: Detergents are more effective cleansing agents than soaps in hard water.
Reason: Calcium and magnesium salts of detergents are water soluble.
(a) Assertion and Reason are correct, Reason explains the Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains the Assertion.

Question 2.
Assertion: Alkanes are saturated hydrocrabons.
Reason: Hydrocarbons consits of covalnet bonds.
(a) Assertion and Reason are correct, Reason explains the Assertion .
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

V. Short answer questions:

Question 1.
Name the simplest ketone and give its structural formula.
Answer:
The simplest ketone is Propanone.
It’s structural formula:

Question 2.
Classify the following compounds based on the pattern of carbon chain and give their structural formula:
(i) Propane
(ii) Benzene
(iii) Cyclo butane
(iv) Furan.
Answer:

Question 3.
How is ethanoic acid prepared from ethanol? Give the chemical equation.
Answer:
Ethanol is oxidized to ethanoic acid with alkaline KMnO₄ or acidified K₂Cr₂O₇.

Question 4.
How do detergents cause water pollution? Suggest remedial measures to prevent this pollution?
Answer:

• Some detergents having a branched hydrocarbon chain are not fully biodegradable by microorganisms present in water. So, they cause water pollution.
• They have straight hydrocarbon chains, in biodegradable detergents, which can be easily degraded by bacteria.

Question 5.
Differentiate soaps and detergents.
Answer:

VI. Long answer questions.

Question 1.
What is called a homologous series? Give any three of its characteristics?
Answer:
A homologous series is a group or a class of organic compounds having the same general formula and similar chemical properties in which the successive members differ by a – CH₂ group.
Characteristics of homologous series:

• All members of a homologous series contain the same elements and functional group.
• All members of a homologous series can be prepared by a common method.
• Chemical properties of the members of a homologous series are similar.

Question 2.
Arrive at, systematically, the IUPAC name of the compound: CH₃-CH₂– CH₂-OH.
Answer:
Step 1: The parent chain consists of 3 carbon atoms. The root word is ‘Prop’.
Step 2: There are single bonds between the carbon atoms of the chain. So, the primary suffix is ‘ane’.
Step 3: Since, the compound contains – OH group, it is an alcohol. The carbon chain is numbered from the end which is closest to – OH group. (Rule 3)

Step 4: The locant number of – OH group is l and thus the secondary suffix is ‘l-ol’.
The name of the compound is Prop + ane + (l – ol) = Propan-l-ol

Question 3.
How is ethanol manufactured from sugarcane?
Answer:
Ethanol is manufactured in industries by the fermentation of molasses, which is a by-product obtained during the manufacture of sugar from sugarcane. Molasses is a dark coloured syrupy liquid left after the crystallization of sugar from the concentrated sugarcane juice. Molasses contain about 30% of sucrose, which cannot be separated by crystallization. It is converted into ethanol by the following steps:
(i) Dilution of molasses : Molasses is first diluted with water to bring down the concentration of sugar to about 8 to 10 percent.

(ii) Addition of Nitrogen source : Molasses usually contains enough nitrogenous matter to act as food for yeast during the fermentation process. If the nitrogen content of the molasses is poor, it may be fortified by the addition of ammonium sulphate or ammonium phosphate.

(iii) Addition of YeastrThe solution obtained in step (ii) is collected in large ‘fermentation tanks’ and yeast is added to it. The mixture is kept at about 303K for a few days. During this period, the enzymes invertase and zymase present in yeast, bring about the conversion of sucrose into ethanol.

The fermented liquid is technically called wash.

(iv) Distillation of ‘Wash’: The fermented liquid (i.e., wash), containing 15 to 18 percent alcohol, is now subjected to fractional distillation. The main fraction drawn is an aqueous solution of ethanol which contains 95.5% of ethanol and 4.5% of water. This is called rectified spirit. This mixture is then refluxed over quicklime for about 5 to 6 hours and then allowed to stand for 12 hours. On distillation of this mixture, pure alcohol (100%) is obtained. This is called absolute alcohol.

Question 4.
Give the balanced chemical equation of the following reactions:
(i) Neutralization of NaOH with ethanoic acid.
Answer:

(ii) Evolution of carbon dioxide by the action of ethanoic acid with NaHCO₃.
Answer:

(iii) Oxidation of ethanol by acidified potassium dichromate.
Answer:

(iv) Combustion of ethanol.
Answer:

Question 5.
Explain the mechanism of cleansing action of soap.
Answer:
A soap molecule contains two chemically distinct parts that interact differently with water. It has one polar end, which is a short head with a carboxylate group (-COONa) and one non – polar end having the long tail made of the hydrocarbon chain.

The polar end is hydrophilic (Water-loving) in nature and this end is attracted towards the water. The non – polar end is hydrophobic (Water hating) in nature and it is attracted towards dirt or oil on the cloth, but not attracted towards the water. Thus, the hydrophobic part of the soap molecule traps the dirt and the hydrophilic part makes the entire molecule soluble in water.

When soap or detergent is dissolved in water, the molecules join together as clusters called ‘micelles’. Their long hydrocarbon chains attach themselves to the oil and dirt. The dirt is thus surrounded by the non-polar end of the soap molecules. The charged carboxylate end of the soap molecules makes the micelles soluble in water. Thus, the dirt is washed away with the soap.

VII. Hot Questions.

Question 1.
The molecular formula of an alcohol is C₄H₁₀O. The locant number of its -OH group is 2.
(i) Draw its structural formula.
Answer:

(ii) Give its IUPAC name.
Answer:
Butan-2-ol

(iii) Is it saturated or unsaturated?
Answer:
Saturated

Question 2.
An organic compound ‘A’ is widely used as a preservative and has the molecular formula C₂H₄O₂. This compound reacts with ethanol to form a sweet smelling compound ‘B’.
(i) Identify the compound ‘A’.
Answer:
Organic Compound ‘A’ with the molecules formula C₂ H₄ O₂ which is a preservative is acetic acid (or) ethanoic acid.
A – CH₃COOH

(ii) Write the chemical equation for its reaction with ethanol to form compound ‘B’.
Answer:

B – Ethyl ethanoate (ester – sweet smelling)

(iii) Name the process.
Answer:
Esterification

Samacheer Kalvi 10th Science Carbon and its Compounds Additional Important Questions and Answers

I. Choose the best answer.

Question 1.
The general formula of alkane series is:
(a) C_nH_2n
(b) C_nH_2n-1
(C) C_nH_2n+2
(d) C_nH_2n-2
Answer:
(C) C_nH_2n+2

Question 2.
Organic compounds are _____ in nature.
(a) flammable
(b) inflammable
(c) heavy
(d) light.
Answer:
(b) inflammable

Question 3.
The Heterocyclic compound is:
(a) Benzene
(b) Pyridine
(c) Naphthalene
(d) Camphor
Answer:
(b) Pyridine

Question 4.
Pick out the unsaturated compound from the following ______.
(a) CH₃ – CH₂ – CH₃
(b) CH₃ – CH = CH₂
(c) \(\mathrm{CH}_{3}-\mathrm{C} \equiv \mathrm{CH}\)
(d) both (b) and (c).
Answer:
(d) both (b) and (c).

Question 5.
……….. will decolourise Br₂/H₂O.
(a) Methane
(b) Pent-2-ene
(c) Ethyl alcohol
(d) Ethanal
Answer:
(b) Pent-2-ene

Question 6.
The simplest alkane is ______.
(a) Ethane
(b) Ethyne
(c) Propane
(d) Methane.
Answer:
(d) Methane.

Question 7.
……….. is the prefix used for -NH₂ Group.
(a) Fluoro
(b) Methyl
(c) Amino
(d) Nitro
Answer:
(c) Amino

Question 8.
The IUPAC name of an organic compound is Pentan-2-one. The secondary suffix is:
(a) Pentan
(b) an
(c) -one
(d) -2-
Answer:
(c) -one

Question 9.
Molasses is fortified with ………… to increase the nitrogen content.
(a) (NH₄)₂SO₄ (or) (NH₄)₃PO₄
(b) (NH₄)₂CO₃ (or) NH₄Cl
(c) (NH₄)₂CO₃ (or) NH₄OH
(d) None of the above
Answer:
(a) (NH₄)₂SO₄ (or) (NH₄)₃PO₄

Question 10.
Which one of the following is a general formula for alkyne?
(a) C_nH_2n
(b) C_nH_2n+2
(c) C_nH_2n-2
(d) C_nH_n
Answer:
(c) C_nH_2n-2

II. Fill in the blanks.

1. The common difference between the successive member of the homologous series if ……….. group.
2. Denatured spirit is a mixture of ethanol and …………
3. Methane gas is produced when the sodium salt of ethanoic acid is ………… with soda lime.
4. For coagulating rubber from latex ………… is used.
5. ………… is added to prevent the caking of the detergent powder.
6. When a soap or detergent is added to water the moleculer cluster together to form ……….
7. The terminal functional group among aldehydes and ketones is ………..
8. On dehydrogenation of ethanol with Cu/573 K it gives ………… gas.
9. ……… converts glucose into ethanol and carbondi-oxide.
10. The structural formula of Pentanoic acid is …………
Answer:
1. -CH₂
2. pyridine
3. decarboxylated
4. ethanoic acid
5. Na₂SO₄ or Sodium sulphate
6. micelles
7. aldehyde
8. H₂
9. Zymase
10. CH₃CH₂CH₂CH₂COOH

III Match the following:

Question 1.
Match the column I and column II.

Answer:
A. (ii)
B. (iii)
C. (v)
D. (i)
E. (iv)

Question 2.
Match the column I and column II.

Answer:
A. (v)
B. (iv)
C. (i)
D. (iii)
E. (ii)

IV Assertion and Reason.

Answer the following questions using the data given below:
Question 1.
Assertion: Alkynes decolourise bromine water.
Reason: Alkynes are unsaturated compounds.
(a) Assertion and Reason are correct, Reason explains Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains Assertion.

Question 2.
Assertion: Denaturation of ethanol makes it unfit for drinking purpose.
Reason: Ethanol is mixed with Pyridine for denaturation.
(a) Assertion and Reason are correct, Reason explains Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(a) Assertion and Reason are correct, Reason explains Assertion.

Question 3.
Assertion: Organic compounds contains covalent bond.
Reason: Organic compounds have low melting and boiling points.
(a) Assertion and Reason are correct, Reason explains Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.

Question 4.
Assertion: Due to catenation a large number of carbon compounds are formed.
Reason: Carbon compounds show the property of allotropy.
(a) Assertion and Reason are correct, Reason explains Assertion.
(b) Assertion is correct, Reason is wrong.
(c) Assertion is wrong, Reason is correct.
(d) Assertion and Reason are correct, Reason doesn’t explains Assertion.
Answer:
(b) Assertion is correct, Reason is wrong.

V. Short answer questions:

Question 1.
Define isomerism with an example.
Answer:
Isomerism is a phenomenon in which organic compounds having the same molecular formula will have different structural formula.
Eg: for the molecular formula C₂H₆O we can write
CH₃CH₂OH – ethanol
CH₄O CH₃ – Methoxy methane

Question 2.
What are root words?
Answer:
Root words are the basic unit which describes the carbon skeleton. It gives the number of carbon atoms present in the parent chain of the compound and the pattern of their arrangement.

Question 3.
Write The functional group and the secondary suffix of the following compounds.
Answer:

Question 4.
What happens when ethanol is dehydrated with con.H₂SO₄ at 443K?
Answer:
Dehydration (Loss of water): When ethanol is heated with cone. H₂SO₄ at 443K, it loses a water molecule i.e., dehydrated to form ethene.

Question 5.
Write a note on esterification.
Answer:
The reaction of an alcohol with a carboxylic acid gives a compound having fruity odour. This compound is called an ester and the reaction is called esterification. Ethanol reacts with ethanoic acid in the presence of cone. H₂SO₄ to form ethyl ethanoate, an ester.

Question 6.
Write tests to identify the presence of ethanoic acid.
Answer:

1. Ethanoic acid turns blue litmus paper to red.
2. Ethanoic acid gives brisk effervescence when treated with Na₂CO₃
3. Ethanoic acid gives a sweet-smelling compound called ester when treated with ethanol.

Question 7.
Write a note on decarboxylation reaction.
Answer:
Decarboxylation (Removal of CO₂): When a sodium salt of ethanoic acid is heated with soda lime (solid mixure of 3 parts of NaOH and 1 part of CaO), methane gas is formed.

Question 8.
What is hard soap?
Answer:
Soaps, which are prepared by the saponification of oils or fats with caustic soda (sodium hydroxide), are known as hard soaps. They are usually used for washing purposes.

Question 9.
Why ordinary soap is not suitable for using with hard water?
Answer:
Ordinary soaps when treated with hard water, precipitate as salts of calcium and magnesium. They appear at the surface of the cloth as sticky grey scum. Thus, the soaps cannot be used conveniently in hard water.

Question 10.
What are the advantages of detergents over soaps?
Answer:
Detergents are better than soaps because of they:

1. can be used in both hard and soft water and can clean more effectively in hard water than soap.
2. can also be used in saline and acidic water.
3. do not leave any soap scum on the tub or clothes.
4. dissolve freely even in cool water and rinse freely in hard water.
5. can be used for washing woollen garments, whereas soap cannot be used.
6. have a linear hydrocarbon chain, which is biodegradable.
7. are active emulsifiers of motor grease.
8. do an effective and safe cleaning, keeping even synthetic fabrics brighter and whiter.

VI. Long answer questions.

Question 1.
Write the IUPAC name of the following compounds
Answer:

Question 2.
Write the characteristics of organic compounds.
Answer:

1. Organic compounds have a high molecular weight and a complex structure.
2. They are mostly insoluble in water but soluble in organic solvents such as ether, carbon tetrachloride, toluene, etc.
3. They are highly inflammable in nature.
4. Organic compounds are less reactive compared to inorganic compounds. Hence, the reactions involving organic compounds proceed at slower rates.
5. Mostly organic compounds form covalent bonds in nature.
6. They have a lower melting point and boiling point when compared to inorganic compounds
7. They exhibit the phenomenon of isomerism, in which a single molecular formula represents several organic compounds that differ in their physical and chemical properties
8. They are volatile in nature.
9. Organic compounds can be prepared in the laboratory.

Question 3.
List the advantages of detergents over soaps.
Answer:

1. Can be used in both hard and soft water and can clean more effectively in hard water than soap.
2. Can also be used in saline and acidic water.
3. Do not leave any soap scum on the tub or clothes.
4. Dissolve freely even in cool water and rinse freely in hard water.
5. Can be used for washing woollen garments, where as soap cannot be used.
6. Have a linear hydrocarbon chain, which is biodegradable.
7. Are active emulsifiers of motor grease.
8. Do an effective and safe cleansing, keeping even synthetic fabrics brighter and whiter.

Question 4.
Draw the schematic diagram for the classification of organic compounds based on the pattern of carbon chain with example.
Answer:

Question 5.
Explain the manufacture of soap.
Answer:
Manufacture of soap by Kettle Process This is the oldest method. But, it is still widely used in the small scale preparation of soap. There are mainly, two steps to be followed in this process.

1. Saponification of oil: The oil, which is used in this process, is taken in an iron tank (kettle). The alkaline solution (10%) is added into the kettle, a little in excess. The mixture is boiled by passing steam through it. The oil gets hydrolysed after several hours of boiling. This process is called Saponification.

2. Salting out of soap: Common salt is then added to the boiling mixture. Soap is finally precipitated in the tank. After several hours the soap rises to the top of the liquid as a ‘curdy mass’. The neat soap is taken off from the top. It is then allowed to cool down.

Question 6.
Ethanol is heated with excess con.H₂SO₄ at 443K.
(a) Name the reaction that occurs and explain it.
Answer:
Dehydration (Loss of water).
When ethanol is heated with conc.H₂SO₄ at 443K, it loses a water molecule i.e., dehydrated to form ethene.

Answer:

(c) What is the product formed? What happen when this gas is passed through Br₂/H₂O.
Answer:
Ethene gas.
When it is passed through Br₂/H₂O it gets decolourised because it is an unsaturated compound.

(d) Why does no decolonization occurs when ethanol is treated with Br₂/H₂O?
Answer:
Ethanol is a saturated compound. Therefore no decolourisation occurs.

VII. Hot Questions.

Question 1.
Organic compounds A and B are isomers with the molecular formula C₂H₆O (A) liberates H2 gas when it reacts with metallic sodium whereas (B) does not. Compound (A) reacts with ethanoic acid and forms a fruity smelling compound (C). Identify A, B and C and explain the reactions.
Answer:
(A) and (B) are compounds with same molecular formula C₂H₆O.
(A) reacts with metallic Na and liberates H₂↑
∴ (A) is ethanol [CH₃CH₂OH]
(B) is methoxy methane [CH₃OCH₃]

(A) reacts with ethanoic acid and forms ester.

(A) Ethanol, CH₃CH₂OH
(B) Methoxy methane, CH₃OCH₃
(C) Ethyl ethanoate, CH₃COOC₂H₅

Question 2.
Write the IUPAC names of the following compounds.
Answer:

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Samacheer Kalvi 10th Tamil Book Solutions Guide Pdf Free Download

Tamilnadu State Board Samacheer Kalvi 10th Tamil Book Back Answers Solutions Guide Term 1, 2, 3.

Samacheer Kalvi 10th Tamil Book Back Answers

• Chapter 1.1 அன்னை மொழியை
• Chapter 1.2 தமிழ்சொல் வளம்
• Chapter 1.3 இரட்டுற மொழிதல்
• Chapter 1.4 உரைநடையின் அணிநலன்கள்
• Chapter 1.5 எழுத்து சொல்
• Chapter 2.1 கேட்கிறதா ஏன்குரல்!
• Chapter 2.2 காற்றை வா!
• Chapter 2.3 முல்லைப்பாட்டு
• Chapter 2.4 புயலிலே ஒரு தோணி
• Chapter 2.5 தொகைநிலைத் தொடர்கள்
• Chapter 3.1 விருந்து போற்றுதும்!
• Chapter 3.2 காசிக்காண்டம்
• Chapter 3.3 மலைபடுகடாம்
• Chapter 3.4 கோபல்லபுரத்து மக்கள்
• Chapter 3.5 தொகாநிலைத் தொடர்கள்
• Chapter 3.6 திருக்குறள்
• Chapter 4.1 செயற்க்கை நுண்ணறிவு
• Chapter 4.2 பெருமாள் திருமொழி
• Chapter 4.3 பரிபாடல்
• Chapter 4.4 விண்ணைத் தாண்டிய தன்னம்பிக்கை
• Chapter 4.5 இலக்கணம் – பொது
• Chapter 5.1 மொழிபெயர்ப்புக் கல்வி
• Chapter 5.2 நீதி வெண்பா
• Chapter 5.3 திருவிளையாடற் புராணம்
• Chapter 5.4 புதியநம்பிக்கை
• Chapter 5.5 வினா, விடை வகைகள், பொருள்கோள்
• Chapter 6.1 நிகழ்கலை
• Chapter 6.2 பூத்தொடுத்தல்
• Chapter 6.3 முத்துக்குமாரசாமி பிள்ளைத்தமிழ்
• Chapter 6.4 கம்பராமாயணம்
• Chapter 6.5 பாய்ச்சல்
• Chapter 6.6 அகப்பொருள் இலக்கணம்
• Chapter 6.7 திருக்குறள்
• Chapter 7.1 சிற்றகல் ஒளி (தன்வரலாறு)
• Chapter 7.2 ஏர் புதிதா?
• Chapter 7.3 மெய்க்கீர்த்தி
• Chapter 7.4 சிலப்பதிகாரம்
• Chapter 7.5 மங்கையராய்ப் பிறப்பதற்கே…
• Chapter 7.6 புறப்பொருள் இலக்கணம்
• Chapter 8.1 சங்க இலக்கியத்தில் அறம்
• Chapter 8.2 ஞானம்
• Chapter 8.3 காலக்கணிதம்
• Chapter 8.4 இராமானுசர் (நாடகம்)
• Chapter 8.5 பா-வகை, அலகிடுதல்
• Chapter 9.1 ஜெயகாந்தம் (நினைவு இதழ்)
• Chapter 9.2 சித்தாளு
• Chapter 9.3 தேம்பாவணி
• Chapter 9.4 ஒருவன் இருக்கிறான்
• Chapter 9.5 அணி

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Samacheer Kalvi 10th English Book Back Answers

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Samacheer Kalvi 10th English Book Solutions Prose

• Chapter 1 His First Flight
• Chapter 2 The Night the Ghost Got in
• Chapter 3 Empowered Women Navigating The World
• Chapter 4 The Attic
• Chapter 5 Tech Bloomers
• Chapter 6 The Last Lesson
• Chapter 7 The Dying Detective

Samacheer Kalvi 10th English Book Solutions Poem

• Chapter 1 Life
• Chapter 2 The Grumble Family
• Chapter 3 I am Every Woman
• Chapter 4 The Ant and the Cricket
• Chapter 5 The Secret of the Machines
• Chapter 6 No Men Are Foreign
• Chapter 7 The House on Elm Street

Samacheer Kalvi 10th English Book Solutions Supplementary

• Chapter 1 The Tempest
• Chapter 2 Zigzag
• Chapter 3 The Story of Mulan
• Chapter 4 The Aged Mother
• Chapter 5 A Day in 2889 of an American Journalist
• Chapter 6 The Little Hero of Holland
• Chapter 7 A Dilemma

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TN Samacheer Kalvi 10th Book Back Answers Solutions Guide

• Samacheer Kalvi 10th Maths Guide
• Samacheer Kalvi 10th Science Guide
• Samacheer Kalvi 10th Social Science Guide
• Samacheer Kalvi 10th English Guide
• Samacheer Kalvi 10th Tamil Guide

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Samacheer Kalvi 10th Maths Book Back Answers

Samacheer Kalvi 10th Maths Book with Answers Chapter 1 Relations and Functions

• Chapter 1 Relations and Functions Ex 1.1
• Chapter 1 Relations and Functions Ex 1.2
• Chapter 1 Relations and Functions Ex 1.3
• Chapter 1 Relations and Functions Ex 1.4
• Chapter 1 Relations and Functions Ex 1.5
• Chapter 1 Relations and Functions Ex 1.6
• Chapter 1 Relations and Functions Unit Exercise 1
• Chapter 1 Relations and Functions Additional Questions

Samacheer Kalvi 10th Maths Book Solutions Chapter 2 Numbers and Sequences

• Chapter 2 Numbers and Sequences Ex 2.1
• Chapter 2 Numbers and Sequences Ex 2.2
• Chapter 2 Numbers and Sequences Ex 2.3
• Chapter 2 Numbers and Sequences Ex 2.4
• Chapter 2 Numbers and Sequences Ex 2.5
• Chapter 2 Numbers and Sequences Ex 2.6
• Chapter 2 Numbers and Sequences Ex 2.7
• Chapter 2 Numbers and Sequences Ex 2.8
• Chapter 2 Numbers and Sequences Ex 2.9
• Chapter 2 Numbers and Sequences Ex 2.10
• Chapter 2 Numbers and Sequences Unit Exercise 2
• Chapter 2 Numbers and Sequences Additional Questions

TN 10th Maths Guide Samacheer Kalvi Pdf Free Download Chapter 3 Algebra

• Chapter 3 Algebra Ex 3.1
• Chapter 3 Algebra Ex 3.2
• Chapter 3 Algebra Ex 3.3
• Chapter 3 Algebra Ex 3.4
• Chapter 3 Algebra Ex 3.5
• Chapter 3 Algebra Ex 3.6
• Chapter 3 Algebra Ex 3.7
• Chapter 3 Algebra Ex 3.8
• Chapter 3 Algebra Ex 3.9
• Chapter 3 Algebra Ex 3.10
• Chapter 3 Algebra Ex 3.11
• Chapter 3 Algebra Ex 3.12
• Chapter 3 Algebra Ex 3.13
• Chapter 3 Algebra Ex 3.14
• Chapter 3 Algebra Ex 3.15
• Chapter 3 Algebra Ex 3.16
• Chapter 3 Algebra Ex 3.17
• Chapter 3 Algebra Ex 3.18
• Chapter 3 Algebra Ex 3.19
• Chapter 3 Algebra Unit Exercise 3
• Chapter 3 Algebra Additional Questions

Samacheer Kalvi 10th Maths Guide Pdf Free Download Chapter 4 Geometry

• Chapter 4 Geometry Ex 4.1
• Chapter 4 Geometry Ex 4.2
• Chapter 4 Geometry Ex 4.3
• Chapter 4 Geometry Ex 4.4
• Chapter 4 Geometry Ex 4.5
• Chapter 4 Geometry Unit Exercise 4
• Chapter 4 Geometry Additional Questions

Tamilnadu Board Class 10 Maths Chapter 5 Coordinate Geometry

• Chapter 5 Coordinate Geometry Ex 5.1
• Chapter 5 Coordinate Geometry Ex 5.2
• Chapter 5 Coordinate Geometry Ex 5.3
• Chapter 5 Coordinate Geometry Ex 5.4
• Chapter 5 Coordinate Geometry Ex 5.5
• Chapter 5 Coordinate Geometry Unit Exercise 5
• Chapter 5 Coordinate Geometry Additional Questions

Tamil Nadu State Board 10th Std Maths Chapter 6 Trigonometry

• Chapter 6 Trigonometry Ex 6.1
• Chapter 6 Trigonometry Ex 6.2
• Chapter 6 Trigonometry Ex 6.3
• Chapter 6 Trigonometry Ex 6.4
• Chapter 6 Trigonometry Ex 6.5
• Chapter 6 Trigonometry Unit Exercise 6
• Chapter 6 Trigonometry Additional Questions

10th Samacheer Kalvi Maths Chapter Wise Questions Chapter 7 Mensuration

• Chapter 7 Mensuration Ex 7.1
• Chapter 7 Mensuration Ex 7.2
• Chapter 7 Mensuration Ex 7.3
• Chapter 7 Mensuration Ex 7.4
• Chapter 7 Mensuration Ex 7.5
• Chapter 7 Mensuration Unit Exercise 7
• Chapter 7 Mensuration Additional Questions

Samacheer Kalvi 10th Maths Important Questions Chapter 8 Statistics and Probability

• Chapter 8 Statistics and Probability Ex 8.1
• Chapter 8 Statistics and Probability Ex 8.2
• Chapter 8 Statistics and Probability Ex 8.3
• Chapter 8 Statistics and Probability Ex 8.4
• Chapter 8 Statistics and Probability Ex 8.5
• Chapter 8 Statistics and Probability Unit Exercise 8
• Chapter 8 Statistics and Probability Additional Questions

Samacheer Kalvi 10th Maths Guide in Tamil Medium Pdf Download

Samacheer Kalvi 10th Maths Solution Book Tamil Medium Pdf, 10th Maths Guide in Tamil Medium Pdf Download 2020-2021.

10th Maths Solution Book Pdf Chapter 1 உறவுகளும் சார்புகளும்

• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.1
• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.2
• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.3
• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.4
• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.5
• Chapter 1 உறவுகளும் சார்புகளும் Ex 1.6
• Chapter 1 உறவுகளும் சார்புகளும் Unit Exercise 1

10th Standard Maths Guide Chapter 2 எண்களும் தொடர்வரிசைகளும்

• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.1
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.2
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.3
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.4
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.5
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.6
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.7
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.8
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.9
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Ex 2.10
• Chapter 2 எண்களும் தொடர்வரிசைகளும் Unit Exercise 2

10th Maths Solution Chapter 3 இயற்கணிதம்

• Chapter 3 இயற்கணிதம் Ex 3.1
• Chapter 3 இயற்கணிதம் Ex 3.2
• Chapter 3 இயற்கணிதம் Ex 3.3
• Chapter 3 இயற்கணிதம் Ex 3.4
• Chapter 3 இயற்கணிதம் Ex 3.5
• Chapter 3 இயற்கணிதம் Ex 3.6
• Chapter 3 இயற்கணிதம் Ex 3.7
• Chapter 3 இயற்கணிதம் Ex 3.8
• Chapter 3 இயற்கணிதம் Ex 3.9
• Chapter 3 இயற்கணிதம் Ex 3.10
• Chapter 3 இயற்கணிதம் Ex 3.11
• Chapter 3 இயற்கணிதம் Ex 3.12
• Chapter 3 இயற்கணிதம் Ex 3.13
• Chapter 3 இயற்கணிதம் Ex 3.14
• Chapter 3 இயற்கணிதம் Ex 3.15
• Chapter 3 இயற்கணிதம் Ex 3.16
• Chapter 3 இயற்கணிதம் Ex 3.17
• Chapter 3 இயற்கணிதம் Ex 3.18
• Chapter 3 இயற்கணிதம் Ex 3.19
• Chapter 3 இயற்கணிதம் Ex 3.20
• Chapter 3 இயற்கணிதம் Unit Exercise 3

Samacheer Kalvi Guru 10th Maths Chapter 4 வடிவியல்

• Chapter 4 வடிவியல் Ex 4.1
• Chapter 4 வடிவியல் Ex 4.2
• Chapter 4 வடிவியல் Ex 4.3
• Chapter 4 வடிவியல் Ex 4.4
• Chapter 4 வடிவியல் Ex 4.5
• Chapter 4 வடிவியல் Unit Exercise 4

Samacheer Kalvi 10th Maths Book Back Answers Chapter 5 ஆயத்தொலை வடிவியல்

• Chapter 5 ஆயத்தொலை வடிவியல் Ex 5.1
• Chapter 5 ஆயத்தொலை வடிவியல் Ex 5.2
• Chapter 5 ஆயத்தொலை வடிவியல் Ex 5.3
• Chapter 5 ஆயத்தொலை வடிவியல் Ex 5.4
• Chapter 5 ஆயத்தொலை வடிவியல் Ex 5.5
• Chapter 5 ஆயத்தொலை வடிவியல் Unit Exercise 5

Tenth Maths Guide Chapter 6 முக்கோணவியல்

• Chapter 6 முக்கோணவியல் Ex 6.1
• Chapter 6 முக்கோணவியல் Ex 6.2
• Chapter 6 முக்கோணவியல் Ex 6.3
• Chapter 6 முக்கோணவியல் Ex 6.4
• Chapter 6 முக்கோணவியல் Ex 6.5
• Chapter 6 முக்கோணவியல் Unit Exercise 6

10th Samacheer Maths Solution Chapter 7 அளவியல்

• Chapter 7 அளவியல் Ex 7.1
• Chapter 7 அளவியல் Ex 7.2
• Chapter 7 அளவியல் Ex 7.3
• Chapter 7 அளவியல் Ex 7.4
• Chapter 7 அளவியல் Ex 7.5
• Chapter 7 அளவியல் Unit Exercise 7

Samacheer 10th Maths Guide Chapter 8 புள்ளியியலும் நிகழ்தகவும்

• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Ex 8.1
• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Ex 8.2
• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Ex 8.3
• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Ex 8.4
• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Ex 8.5
• Chapter 8 புள்ளியியலும் நிகழ்தகவும் Unit Exercise 8

We hope these Tamilnadu State Board Samacheer Kalvi Class 10th Maths Book Solutions Answers Guide Pdf Free Download in English Medium and Tamil Medium will help you get through your subjective questions in the exam.

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Samacheer Kalvi 10th Social Science Book Back Answers

Tamilnadu State Board Samacheer Kalvi 10th Social Science Book Back Answers Solutions Guide Volume 1, 2.

Samacheer Kalvi 10th Social Science History Book Solutions

• Chapter 1 Outbreak of World War I and Its Aftermath
• Chapter 2 The World Between Two World Wars
• Chapter 3 World War II
• Chapter 4 The World after World War II
• Chapter 5 Social and Religious Reform Movements in the 19th Century
• Chapter 6 Early Revolts against British Rule in Tamil Nadu
• Chapter 7 Anti-Colonial Movements and the British of Nationalism
• Chapter 8 Nationalism: Gandhian Phase
• Chapter 9 Freedom Struggle in Tamil Nadu
• Chapter 10 Social Transformation in Tamil Nadu

Samacheer Kalvi 10th Social Science Geography Book Solutions

• Chapter 1 India: Location, Relief and Drainage
• Chapter 2 Climate and Natural Vegetation of India
• Chapter 3 Components of Agriculture
• Chapter 4 Resources and Industries
• Chapter 5 India: Population, Transport, Communication, and Trade
• Chapter 6 Physical Geography of Tamil Nadu
• Chapter 7 Human Geography of Tamil Nadu

Samacheer Kalvi 10th Social Science Civics Book Solutions

• Chapter 1 Indian Constitution
• Chapter 2 Central Government
• Chapter 3 State Government
• Chapter 4 India’s Foreign Policy
• Chapter 5 India’s International Relations

Samacheer Kalvi 10th Social Science Economics Book Solutions

• Chapter 1 Gross Domestic Product and its Growth: an Introduction
• Chapter 2 Globalization and Trade
• Chapter 3 Food Security and Nutrition
• Chapter 4 Government and Taxes
• Chapter 5 Industrial Clusters in Tamil Nadu

10th Social Science Guide Book Back Questions Tamil Medium with Answers

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10th Social Science Book Back Answers வரலாறு

• Chapter 1 முதல் உலகப்போரின் வெடிப்பும் அதன் பின்விளைவுகளும்
• Chapter 2 இரு உலகப்போர்களுக்கு இடையில் உலகம்
• Chapter 3 இரண்டாம் உலகப்போர்
• Chapter 4 இரண்டாம் உலகப்போருக்குப் பிந்தைய உலகம்
• Chapter 5 19ஆம் நூற்றாண்டில் சமூக, சமய சீர்திருத்த இயக்கங்கள்
• Chapter 6 ஆங்கிலேய ஆட்சிக்கு எதிராக தமிழகத்தில் நிகழ்ந்த தொடக்ககால கிளர்ச்சிகள்
• Chapter 7 காலனியத்துக்கு எதிரான இயக்கங்களும் தேசியத்தின் தோற்றமும்
• Chapter 8 தேசியம்: காந்திய காலகட்டம்
• Chapter 9 தமிழ்நாட்டில் விடுதலைப் போராட்டம்
• Chapter 10 தமிழ்நாட்டில் சமூக மாற்றங்கள்

Samacheer Kalvi 10th Social Book Solutions புவியியல்

• Chapter 1 இந்தியா – அமைவிடம், நிலத்தோற்றம் மற்றும் வடிகாலமைப்பு
• Chapter 2 இந்தியா – காலநிலை மற்றும் இயற்கைத் தாவரங்கள்
• Chapter 3 இந்தியா – வேளாண்மை
• Chapter 4 இந்தியர் – வளங்கள் மற்றும் தொழிலகங்கள்
• Chapter 5 இந்தியா – மக்கள் தொகை, போக்குவரத்து, தகவல் தொடர்பு மற்றும் வணிகம்
• Chapter 6 தமிழ்நாடு – இயற்கைப் பிரிவுகள்
• Chapter 7 தமிழ்நாடு – மானுடப் புவியியல்

10th Samacheer Social Guide குடிமையியல்

• Chapter 1 இந்திய அரசியலமைப்பு
• Chapter 2 நடுவண் அரசு
• Chapter 3 மாநில அரசு
• Chapter 4 இந்தியாவின் வெளியுறவுக் கொள்கை
• Chapter 5 இந்தியாவின் சர்வதேச உறவுகள்

Social Science 10th Guide பொருளியல்

• Chapter 1 மொத்த உள்நாட்டு உற்பத்தி மற்றும் அதன் வளர்ச்சி: ஓர் அறிமுகம்
• Chapter 2 உலகமயமாதல் மற்றும் வர்த்தகம்
• Chapter 3 உணவு பாதுகாப்பு மற்றும் ஊட்டச்சத்து
• Chapter 4 அரசாங்கமும் வரிகளும்
• Chapter 5 தமிழ்நாட்டில் தொழில்துறை தொகுப்புகள்

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Subject Matter Experts at SamacheerKalvi.Guide have created Tamil Nadu State Board Samacheer Kalvi 10th Science Book Answers Solutions Guide Pdf Free Download in English Medium and Tamil Medium are part of Samacheer Kalvi 10th Books Solutions.

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Samacheer Kalvi 10th Science Book Solutions Guide Pdf Free Download

Samacheer Kalvi 10th Science Book Back Answers

Tamilnadu State Board Samacheer Kalvi 10th Science Book Back Answers Solutions Guide.

Samacheer Kalvi 10th Science Physics Book Solutions

• Chapter 1 Laws of Motion
• Chapter 2 Optics
• Chapter 3 Thermal Physics
• Chapter 4 Electricity
• Chapter 5 Acoustics
• Chapter 6 Nuclear Physics

Samacheer Kalvi 10th Science Chemistry Book Solutions

• Chapter 7 Atoms and Molecules
• Chapter 8 Periodic Classification of Elements
• Chapter 9 Solutions
• Chapter 10 Types of Chemical Reactions
• Chapter 11 Carbon and its Compounds

Samacheer Kalvi 10th Science Biology Book Solutions

• Chapter 12 Plant Anatomy and Plant Physiology
• Chapter 13 Structural Organisation of Animals
• Chapter 14 Transportation in Plants and Circulation in Animals
• Chapter 15 Nervous System
• Chapter 16 Plant and Animal Hormones
• Chapter 17 Reproduction in Plants and Animals
• Chapter 18 Heredity
• Chapter 19 Origin and Evolution of Life
• Chapter 20 Breeding and Biotechnology
• Chapter 21 Health and Diseases
• Chapter 22 Environmental Management

Samacheer Kalvi 10th Science Computer Science Book Solutions

• Chapter 23 Visual Communication

10th New Science Book Back Questions Tamil Medium with Answers

10th Samacheer Kalvi Science Book Back Answers Tamil Medium, 10th Science Guide in Tamil Medium Pdf Free Download 2021-2022, 10th Science Book Back Answers in Tamil Medium.

Samacheer Kalvi 10th Science Book Solutions Physics

• Chapter 1 இயக்க விதிகள்
• Chapter 2 ஒளியியல்
• Chapter 3 வெப்ப இயற்பியல்
• Chapter 4 மின்னோட்டவியல்
• Chapter 5 ஒலியியல்
• Chapter 6 அணுக்கரு இயற்பியல்

Tenth Science Guide Chemistry

• Chapter 7 அணுக்களும் மூலக்கூறுகளும்
• Chapter 8 தனிமங்களின் ஆவர்த்தன வகைப்பாடு
• Chapter 9 கரைசல்கள்
• Chapter 10 வேதிவினைகளின் வகைகள்
• Chapter 11 கார்பனும் அதன் சேர்மங்களும்

Science Guide 10th Class Biology

• Chapter 12 தாவர உள்ளமைப்பியல் மற்றும் தாவர செயலியல்
• Chapter 13 உயிரினங்களின் அமைப்பு நிலைகள்
• Chapter 14 தாவரங்களின் கடத்துதல் மற்றும் விலங்குகளின் சுற்றோட்டம்
• Chapter 15 நரம்பு மண்டலம்
• Chapter 16 தாவர மற்றும் விலங்கு ஹார்மோன்கள்
• Chapter 17 தாவரங்கள் மற்றும் விலங்குகளில் இனப்பெருக்கம்
• Chapter 18 மரபியல்
• Chapter 19 உயிரின் தோற்றமும் பரிணாமமும்
• Chapter 20 இனக்கலப்பு மற்றும் உயிரித்தொழில்நுட்பவியல்
• Chapter 21 உடல் நலம் மற்றும் நோய்கள்
• Chapter 22 சுற்றுச்சூழல் மேலாண்மை

Samacheer Kalvi 10th Science Book Solutions Computer Science

• Chapter 23 காட்சித் தொடர்பு

We hope these Tamilnadu State Board Samacheer Kalvi Class 10th Science Book Solutions Answers Guide Pdf Free Download in English Medium and Tamil Medium will help you get through your subjective questions in the exam.

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Students can Download Samacheer Kalvi 10th Maths Model Question Paper 5 English Medium Pdf, Samacheer Kalvi 10th Maths Model Question Papers helps you to revise the complete Tamilnadu State Board New Syllabus, helps students complete homework assignments and to score high marks in board exams.

Tamil Nadu Samacheer Kalvi 10th Maths Model Question Paper 5 English Medium

Instructions

• The question paper comprises of four parts.
• You are to attempt all the parts. An internal choice of questions is provided wherever applicable.
• All questions of Part I, II, III and IV are to be attempted separately.
• Question numbers 1 to 14 in Part I are Multiple Choice Quèstions of one-mark each. These are to be answered by choosing the most suitable answer from the given four alternatives and.writing the option code and the corresponding answer.
• Question numbers 15 to 28 in Part II àre two-marks questions. These are to be answered in about one or two sentences.
• Question numbers 29 to 42 in Part III are five-marks questions. These are to be answered in about three to five short sentences.
• Question numbers 43 to 44 in Part IV are eight-marks questions. These are to be answered in detail. Draw diagrams wherever necessary.

Time: 3 Hours
Maximum Marks: 100

PART – I

I. Choose the correct answer. Answer all the questions. [14 × 1 =14]

Question 1.
The range of the relation R = {(x, x²) x is a prime number less than 13} is ………… .
(1) {2, 3, 5, 7}
(2) (2, 3, 5, 7, 11}
(3) {4,9,25,49, 121}
(4) {1, 4, 9, 25, 49, 121}
Answer:
(3) {4,9,25,49, 121}

Question 2.
If g = {(1,1),(2, 3),(3,5),(4,7)} is a function given by g(x) = αx + β then the values of α and β are ……….. .
(1) (-1,2)
(2) (2,-1)
(3) (-1,-2)
(4) (1,2)
Answer:
(2) (2,-1)

Question 3.
The sum of the exponents of the prime factors in the prime factorization of 1729 is ……….. .
(1) 1
(2) 2
(3) 3
(4) 4
Answer:
(3) 3

Question 4.
The next term of the sequence \(\frac{3}{16}, \frac{1}{8}, \frac{1}{12}, \frac{1}{18}\) is ……….. .
(1) \(\frac{1}{24}\)
(2) \(\frac{1}{27}\)
(3) \(\frac{2}{3}\)
(4) \(\frac{1}{81}\)
Answer:
(2) \(\frac{1}{27}\)

Question 5.
If (x – 6) is the HCF of x² – 2x – 24 and x² – kx – 6 then the value of k is ……….. .
(1) 3
(2) 5
(3) 6
(4) 8
Answer:
(2) 5

Question 6.
The solution of (2x – 1)² = 9 is equal to ……….. .
(1) -1
(2) 2
(3) -1,2
(4) None of these
Answer:
(3) -1,2

Question 7.
In a given figure ST || QR, PS = 2 cm and SQ = 3 cm. Then the ratio of the area of ∆PQR to the area of ∆PST is ……….. .

(1) 25 : 4
(2) 25 : 7
(3) 25 :11
(4) 25 : 13
Answer:
(1) 25 : 4

Question 8.
The slope of the line joining (12, 3), (4, a) is \(\frac { 1 }{ 8 }\). The value of ‘a’ is ……….. .
(1) 1
(2) 4
(3) -5
(4) 2
Answer:
(4) 2

Question 9.
If sin θ + cos θ = a and sec θ + cosec θ = b, then the value of b (a² – 1) is equal to ……….. .
(1) 2 a
(2) 3 a
(3) 0
(4) 2 ab
Answer:
(1) 2 a

Question 10.
The curved surface area of a right circular cone of height 15 cm and base diameter 16 cm is ……….. .
(1) 60π cm²
(2) 68π cm²
(3) 120π cm²
(4) 136π cm²
Answer:
(4) 136π cm²

Question 11.
The sum of all deviations of the data from its mean is ……….. .
(1) always positive
(2) always negative
(3) zero
(4) non-zero integer
Answer:
(3) zero

Question 12.
If \(\left( \begin{matrix} x+y & x-y \\ 7 & 6 \end{matrix} \right) =\left( \begin{matrix} 10 & 2 \\ 7 & z \end{matrix} \right) \) then x, y, z are ……….. .
(1) 4, 6, 6
(2) 6, 6, 4
(3) 6, 4, 6
(4) 4, 4, 6
Answer:
(3) 6, 4, 6

Question 13.
If the n^th term of a sequence is 100n + 10 then the sequence is ……….. .
(1) an A.P.
(2) a G.P.
(3) a constant sequence
(4) neither A.P. nor G.P.
Answer:
(1) an A.P.

Question 14.
Probability of getting 3 heads or 3 tails in tossing a coin 3 times is ……….. .
(1) \(\frac { 1 }{ 8 }\)
(2) \(\frac { 1 }{ 4 }\)
(3) \(\frac { 3 }{ 8 }\)
(4) \(\frac { 1 }{ 2 }\)
Answer:
(2) \(\frac { 1 }{ 4 }\)

PART – II

II. Answer any ten questions. Question No. 28 is compulsory. [10 × 2 = 20]

Question 15.
Let A = {x ∈ W / x < 2}, B = {x ∈ N / 1 < x ≤ 4} and C = {3, 5} find the value of (A × C) ∪ (B × C)
Answer:
A × C = {0,1} × {3,5}
= {(0,3 (0,5) (1,3) (1,5)}
B × C= (2,3,4) × (3,5)
= {(2,3) (2,5) (3,3) (3,5) (4,3) (4,5)}
(A × C) ∪ (B × C) = {(0,3) (0,5) (1,3) (1,5) (2,3) (2,5) (3,3) (3,5) (4,3) (4,5)}

Question 16.
Find k if fof(k) = 5 where f(k) = 2k – 1.
Answer:
fof(k) = f(f(k)) = 2(2k – 1)-1 = 4k – 3.
Thus, fof(k) = 4k – 3
But, it is given that fof(k) = 5
∴ 4k – 3 = 5 ⇒ k = 2.

Question 17.
Find the sum of the following 6 + 13 + 20 +…. + 97
Answer:
Here a = 6, d = 13 – 6 = 7, l = 97
n = \(\frac{l-a}{d}+1\)
= \(\frac{97-6}{7}+1\) = \(\frac{91}{7}+1\) = 13 + 1 = 14
S_n = \(\frac{n}{2}\)(a + l)
S_n = \(\frac{14}{2}\)(6 + 97) = 7 × 103 = 721

Question 18.
Rekha has 15 square colour papers of sizes 10 cm, 11 cm, 12 cm, …,.24 cm. How much area can be decorated with these colour papers?
Answer:
Area of 15 square colour papers
= 10² + 11² + 12² + …. + 24²
= (1² + 2² + 3² + …. + 24²) – (1² + 2² + 9²)
= \(\frac{24 \times 25 \times 49}{6}-\frac{9 \times 10 \times 19}{6}\)
=4 × 25 × 49 – 3 × 5 × 19
= 4900 – 285
= 4615
Area can be decorated is 4615 cm²

Question 19.
Simplify \(\frac{x+2}{4 y} \div \frac{x^{2}-x-6}{12 y^{2}}\)
Answer:

x² – x – 6 = (x – 3) (x + 2)
= \(\frac{x+2}{4 y} \div \frac{x^{2}-x-6}{12 y^{2}}=\frac{x+2}{4 y}+\frac{(x-3)(x+2)}{12 y^{2}}\)
= \(\frac{(x+2)}{4 y} \times \frac{12 y^{2}}{(x-3)(x+2)}\)
= \(\frac{3 y}{x-3}\)

Question 20.
Solve \(\frac{x}{x-1}+\frac{x-1}{x}=2 \frac{1}{2}\)
Answer:
Let y = \(\frac{x}{x-1}\) then \(\frac{1}{y}=\frac{x-1}{x}\)
Therefore, \(\frac{x}{x-1}+\frac{x-1}{x}=2 \frac{1}{2}\) becomes \(y+\frac{1}{y}=\frac{5}{2}\)
2y² – 5y + 2 = 0 then, y = \(\frac{1}{2}, 2\)
\(\frac{x}{x-1}=\frac{1}{2}\) we get, 2x = x – 1 implies x = – 1
\(\frac{x}{x-1}=2\) we get, x = 2x – 2 implies x = 2
∴ The roots are x = -1, 2

Question 21.
Construct a 3 × 3 matrix whose elements are given by a_ij = |i – 2j|
Answer:
a_ij = |i – 2j|
The general 3 × 3 matrices is
A = \(\left( \begin{matrix} { a }_{ 11 } & { a }_{ 12 } & { a }_{ 13 } \\ { a }_{ 21 } & { a }_{ 22 } & { a }_{ 23 } \\ { a }_{ 31 } & { a }_{ 32 } & { a }_{ 33 } \end{matrix} \right)\)
a₁₁ = |1 – 2(1)| = |1 – 2| = |-1| = 1
a₁₂ = |1 – 2(2)| = |1 – 4| = |-3| = 3
a₁₃ = |1 – 2(3)| = |1 – 6| = |-5| = 5
a₂₁ = |2 – 2(1)| = |2 – 2| = 0
a₂₂ = |2 – 2(2)| = |2 – 4| = |-2| = 2
a₂₃ = |2 – 2(3)| = |2 – 6| = |-4| = 4
a₃₁ = |3 – 2(1)| = |3 – 2| = |1| = 1
a₃₂ = |3 – 2(2)| = |3 – 4| = |-1| = 1
a₃₃ = |3 – 2(3)| = |3 – 6| = |-3| = 3
The required matrix A = \(\left[ \begin{matrix} 1 & 3 & 5 \\ 0 & 2 & 4 \\ 1 & 1 & 3 \end{matrix} \right] \)

Question 22.
The length of the tangent to a circle from a point P, which is 25 cm away from the centre is 24 cm. What is the radius of the circle?
Answer:

Let the radius AB be r. In the right ∆ ABO,
OB² = OA² + AB²
25² = 24² + r²
25² – 24² = r²
(25 + 4) (25 – 24) = r²
r = √49 = 7
Radius of the circle = 7 cm

Question 23.
If the straight lines 12y = – (p + 3)x + 12, 12x – 7y = 16 are perpendicular then find ‘p’.
Answer:
Slope of the first line 12y = -(p + 3)x + 12
y = \(-\frac{(p+3) x}{12}+1\) (comparing with y = mx + c)
Slope of the second line (m₁) = \(\frac{-(p+3)}{12}\)
Slope of the second line 12x – 7y = 16
(m₂) = \(\frac{-a}{b}=\frac{-12}{-7}=\frac{12}{7}\)
Since the two lines are perpemdicular.
m₁ × m₂ = -1
\(\frac{-(p+3)}{12} \times \frac{12}{7}=-1 \Rightarrow \frac{-(p+3)}{7}=-1\)
-(p + 3) = -7
– p – 3 = – 7 ⇒ -p = -7 + 3
– p = -4 ⇒ p = 4
The value of p = 4

Question 24.
Prove that 1 + \(\frac{\cot ^{2} \theta}{1+\csc \theta}\) = cosec θ
Answer:

Question 25.
Find the standard deviation of first 21 natural numbers.
Answer:
Here n = 21
Standard deviation of the first ‘n’ natural numbers,
= \(\sqrt{\frac{n^{2}-1}{12}}\)
1,2,3,4, ……. , 21 = \(\sqrt{\frac{21^{2}-1}{12}}=\sqrt{\frac{441-1}{12}}=\sqrt{\frac{440}{12}}\)
= \(\sqrt{36.666}\) = \(\sqrt{36.67}\)
= 6.055 = 6.06
Standard deviation of first 21 natural numbers = 6.06

Question 26.
How many litres of water will a hemispherical tank hold whose diameter is 4.2m?
Answer:
Radius of the tank = \(\frac{4.2}{2}\) = 2.1 m
Volume of the hemisphere = \(\frac{2}{3}\) πr³ cu. unit
= \(\frac{2}{3} \times \frac{22}{7}\) × 2.1 × 2.1 × 2.1 m³
= 19.404 m³
= 19.4o4 × 1000 litre
= 19,4o4 litres

Question 27.
A two digit number is formed with the digits 2, 5, 9 (repetition is allowed). Find the probability that the number is divisible by 2.
Answer:
Sample space (S) = {22, 25, 29, 55, 59, 52, 99, 92, 95}
n(S) = 9
Let A be the event of getting number divisible by 2
A = {22,52,92}
n(A) = 3
P(A) = \(\frac{n(\mathrm{A})}{n(\mathrm{S})}=\frac{3}{9}=\frac{1}{3}\)

Question 28.
Solve √x + 5 = 2x + 3 using formula method.
Answer:
\(\sqrt{x+5}\) = 2x + 3
\((\sqrt{x+5})^{2}\) = (2x + 3)²
x + 5 = 4x² + 9 + 12x
4x² + 11x + 4 = 0
Here a = 4, b = 11, c = 5
x = \(\frac{-b \pm \sqrt{b^{2}-4 a c}}{2 a}\)
= \(\frac{-11 \pm \sqrt{121-64}}{8}\)
= \(\frac{-11 \pm \sqrt{57}}{8}\)
∴ x = \(\frac{-11+\sqrt{57}}{8}\) ; x = \(\frac{-11-\sqrt{57}}{8}\)

PART – III

III. Answer any ten questions. Question No. 42 is compulsory. [10 × 5 = 50]

Question 29.
An open box is to be made from a square piece of material, 24 cm on a side, by cutting equal squares from the comers and turning up the sides as shown. Express the volume V of the box as a function of x.

Question 30.
Find the greatest number consisting of 6 digits which is exactly divisible by 24,15,36?

Question 31.
The present value of a machine is ₹40,000 and its value depreciates each year by 10%. Find the estimated value of the machine in the 6th year.

Question 32.
The sum of the digits of a three-digit number is 11. If the digits are reversed, the new number is 46 more than five times the old number. If the hundreds digit plus twice the tens digit is equal to the units digit, then find the original three digit number?

Question 33.
Find the square root of the expression \(\frac{4 x^{2}}{y^{2}}+\frac{20 x}{y}+13-\frac{30 y}{x}+\frac{9 y^{2}}{x^{2}}\)

Question 34.
If α, β are the roots of 7x² + ax + 2 = 0 and if β – α = \(\frac { -13 }{ 7 }\) . Find the values of a.

Question 35.
State and prove Angle Bisector Theorem.

Question 36.
A quadrilateral has vertices at A(-4, -2) , B(5, -1) , C(6, 5) and D(-7, 6). Show that the mid-points of its sides form a parallelogram.

Question 37.
Two ships are sailing in the sea on either side of the lighthouse. The angles of depression of two ships as observed from the top of the lighthouse are 60° and 45° respectively.
If the distance between the ships is 200 \(\left(\frac{\sqrt{3}+1}{\sqrt{3}}\right)\) meters, find the height of the light house.

Question 38.
A shuttle cock used for playing badminton has the shape of a frustum of a cone is mounted on a hemisphere. The diameters of the frustum are 5 cm and 2 cm. The height of the entire shuttle cock is 7 cm. Find its external surface area.

Question 39.
Two dice are rolled together. Find the probability of getting a doublet or sum of faces as 4.

Question 40.
Given f(x) = x – 2 ; g(x) = 3x + 5; h(x) = 2x – 3 verify that (goh) of = go (hof)

Question 41.
A 20 m deep well with inner diameter 7 m is dug and the earth from digging is evenly spread out to form a platform 22m by 14m. Find the height of the platform.

Question 42.
The mean and standard deviation of 20 items are found to be 10 and 2 respectively. At the time of checking it was found that an item 12 was wrongly entered as 8. Calculate the correct mean and standard deviation.

PART – IV

IV. Answer all the questions. [2 × 8 = 16]

Question 43.
(a) Construct a triangle similar to a given triangle PQR with its sides equal to \(\frac { 7 }{ 3 }\) of the corresponding sides of the triangle PQR (scale factor \(\frac { 7 }{ 3 }\)).

[OR]

(b) Draw a circle of diameter 6 cm from a point P, which is 8 cm away from its centre. Draw the two tangents PA and PB to the circle and measure their lengths.

Question 44.
(a) Draw the graph of y = x² – 5x – 6 and hence solve x² – 5x – 14 = 0.

[OR]

(b) Solve graphically 2x² + x – 6 = 0.

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