12th Chemistry - Book Back Answers - Unit 10 Surface Chemistry - English Medium Guides

  

 

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Tamil Nadu Board 12th Standard Chemistry - Unit 10: Book Back Answers and Solutions

    This post covers the book back answers and solutions for Unit 10 from the Tamil Nadu State Board 12th Standard Chemistry textbook. These detailed answers have been carefully prepared by our expert teachers at KalviTips.com.

    We have explained each answer in a simple, easy-to-understand format, highlighting important points step by step under the relevant subtopics. Students are advised to read and memorize these subtopics thoroughly. Once you understand the main concepts, you’ll be able to connect other related points with real-life examples and confidently present them in your tests and exams.

    By going through this material, you’ll gain a strong understanding of Unit 10 along with the corresponding book back questions and answers (PDF format).

Question Types Covered:

• 1 Mark Questions: Choose the correct answer, Fill in the blanks, Identify the correct statement, Match the following 
• 2 Mark Questions: Answer briefly 
• 3, 4, and 5 Mark Questions: Answer in detail

All answers are presented in a clear and student-friendly manner, focusing on key points to help you score full marks.

All the best, Class 12 students! Prepare well and aim for top scores. Thank you!

I. Multiple Choice Questions

1. For Freundlich isotherm a graph of log m x is plotted against log p. The slope of the line and its y – axis intercept respectively corresponds to

a) $\raisebox{1ex}{$\mathbf{1}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{n}$}\right.\mathbf{,}\mathbf{K}$

b) $\mathbf{log}\mathbf{ }\raisebox{1ex}{$\mathbf{1}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{n}$}\right.\mathbf{,}\mathbf{K}$

c) $\raisebox{1ex}{$\mathbf{1}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{n}$}\right.\mathbf{,}\mathbf{log}\mathrm{K}$

d) $\mathbf{log}\mathbf{ }\raisebox{1ex}{$\mathbf{1}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{n}$}\right.\mathbf{,}\mathbf{ }\mathbf{log}\mathbf{K}$

Answer Key:

c) $\raisebox{1ex}{$\mathbf{1}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{n}$}\right.\mathbf{,}\mathbf{log}\mathrm{K}$

$\mathrm{ }$ 

2. Which of the following is incorrect for physisorption?

a) reversible

b) increases with increase in temperature

c) low heat of adsorption

d) increases with increase in surface area

Answer Key:

b) increases with increase in temperature

  

3. Which one of the following characteristics are associated with adsorption?

a) DG and DHare negative but DS is positive

b) DGand ΔS are negative but ΔH is positive

c) ΔG is negative but ΔH and ΔS are positive

d) ΔG, ΔH and ΔS all are negative.

Answer Key:

d) ΔG, ΔH and ΔS all are negative.

 

4. Fog is colloidal solution of

a) solid in gas

b) gas in gas

c) liquid in gas

d) gas in liquid

Answer Key:

c) liquid in gas 

  

5. Assertion : Coagulation power of Al³⁺ is more than Na⁺ .

Reason : greater the valency of the flocculating ion added, greater is its power to cause

precipitation

a) if both assertion and reason are true and reason is the correct explanation of assertion.

b) if both assertion and reason are true but reason is not the correct explanation of

assertion.

c) assertion is true but reason is false

d) both assertion and reason are false.

Answer Key:

a) if both assertion and reason are true and reason is the correct explanation of assertion.

  

6. Statement:

To stop bleeding from an injury, ferric chloride can be applied. Which comment about the statement is justified?

a) It is not true, ferric chloride is a poison.

b) It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol

c) It is not true; ferric chloride is ionic and gets into the blood stream.

d) It is true, coagulation takes place because of formation of negatively charged sol with Cl^-.

Answer Key:

b) It is true, Fe³⁺ ions coagulate blood which is a negatively charged sol

 

7. Hair cream is

a) gel

b) emulsion

c) solid sol

d) sol.

Answer Key:

b) emulsion 

  

8. Which one of the following is correctly matched?

a) Emulsion	–	Smoke
b) Gel	–	butter
c) foam	–	Mist
d) whipped cream	–	sol

Answer Key:

(b) Gel-butter 

  

9. The most effective electrolyte for the coagulation of As₂S₃Sol is

a) NaCl

b) Ba(NO₃)₂

c) K₃[Fe(CN)]₆

d) Al₂(SO₄)₃

Answer Key:

d) Al₂(SO₄)₃

  

10. Which one of the is not a surfactant?

a) CH₃ $\mathbf{<b>-</b>}$ (CH₂)₁₅ $\mathbf{<b>-</b> }$$\underset{\mathbf{N}}{\mathbf{+}}$ $\mathbf{<b>-</b> }$(CH₃)₂ CH₂Br

b) b) CH₃ $\mathbf{<b>-</b> }$(CH₂)₁₅ $\mathbf{<b>-</b> }$NH₂

c) CH₃ $\mathbf{<b>-</b> }$(CH₂)₁₆ $\mathbf{<b>-</b> }$CH₂ OSO₂^- Na⁺

d) d) OHC $\mathbf{<b>-</b>}$ (CH₂)₁₄ $\mathbf{<b>-</b> }$CH₂ $\mathbf{<b>-</b> }$COO^- Na⁺

Answer Key:

b) b) CH₃ $\mathbf{<b>-</b> }$(CH₂)₁₅ $\mathbf{<b>-</b> }$NH₂

 

11. The phenomenon observed when a beam of light is passed through a colloidal solution is

a) Cataphoresis

b) Electrophoresis

c) Coagulation

d) Tyndall effect

Answer Key:

d) Tyndall effect

  

12. In an electrical field, the particles of a colloidal system move towards cathode. The coagulation of the same sol is studied using K₂SO₄ (i), Na₃PO₄ (ii),K₄[Fe(CN)₆] (iii) and NaCl (iv) Their coagulating power should be

a) II > I>IV > III

b) III > II > I > IV

c) I > II > III > IV

d) none of these

Answer Key:

b) III > II > I > IV 

  

13. Collodion is a 4% solution of which one of the following compounds in alcohol – ether mixture?

a) Nitroglycerine

b) Cellulose acetate

c) Glycoldinitrate

d) Nitrocellulose

Answer Key:

d) Nitrocellulose

  

14. Which one of the following is an example for homogeneous catalysis?

a) manufacture of ammonia by Haber’s process

b) manufacture of sulphuric acid by contact process

c) hydrogenation of oil

d) Hydrolysis of sucrose in presence of dil HCl

Answer Key:

d) Hydrolysis of sucrose in presence of dil HCl

  

15. Match the following

A) V2O5	i) High density polyethylene
B) Ziegler – Natta	ii) PAN
C) Peroxide	iii) NH3
D) Finely divided Fe	iv) H2SO4

 A         B         C         D

a)         (iv)      (i)        (ii)       (iii)

b)        (i)        (ii)       (iv)      (iii)

c)         (ii)       (iii)     (iv)      (i)

d)        (iii)     (iv)      (ii)       (i)

Answer Key:

a)         (iv)      (i)        (ii)       (iii)

  

16. The coagulation values in millimoles per litre of the electrolytes used for the coagulation of As₂S₃ are given below

(I) (NaCl)=52           (II) ((BaCl )=0.69 2                        (III) (MgSO )=0.22 4

The correct order of their coagulating power is

a) III > II > I

b) I > II > III

c) I > III > II

d) II > III>I

Answer Key:

a) III > II > I 

  

17. Adsorption of a gas on solid metal surface is spontaneous and exothermic, then

a) ΔH increases

b) ΔS increases

c) ΔG increases

d) ΔS decreases

Answer Key:

d) ΔS decreases

 

18. If x is the amount of adsorbate and m is the amount of adsorbent, which of the following relations is not related to adsorption process?

a) $\raisebox{1ex}{$\mathbf{x}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{m}$}\right.$ = f(p)at constant T

b) $\raisebox{1ex}{$\mathbf{x}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{m}$}\right.$ = f(T) at constant P

c) P = f(T) at constant $\raisebox{1ex}{$\mathbf{x}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{m}$}\right.$

d) $\raisebox{1ex}{$\mathbf{x}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{m}$}\right.$ = PT

Answer Key:

d) $\raisebox{1ex}{$\mathbf{x}$}\!\left/ \!\raisebox{-1ex}{$\mathbf{m}$}\right.$ = PT

 

19. On which of the following properties does the coagulating power of an ion depend?

a) Both magnitude and sign of the charge on the ion.

b) Size of the ion alone

c) the magnitude of the charge on the ion alone

d) the sign of charge on the ion alone.

Answer Key:

a) Both magnitude and sign of the charge on the ion.

  

20. Match the following

A) Pure nitrogen	i) Chlorine
B) Haber process	ii) Sulphuric acid
C) Contact process	iii) Ammonia
D) Deacons Process	iv) sodium azide (or) Barium azide

Which of the following is the correct option?

A         B         C         D

a)         (i)        (ii)       (iii)     (iv)

b)        (ii)       (iv)      (i)        (iii)

c)         (iii)     (iv)      (ii)       (i)

d)        (iv)      (iii)     (ii)       (i)

Answer Key:

d)        (iv)      (iii)     (ii)       (i) 

 

II. Short Answer Questions.

12th Chemistry

III. Long Answer Questions. 

12th Chemistry

IV. Exercise.   

12th Chemistry