CBSE Class 12 Chemistry Surface Chemistry Worksheet Set E

 

1. Which of the following electrolyte will havemaximum flocculation value for Fe(OH)₃ sol?

a) NaCl   b) Na₂S   c) (NH₄)₃PO₄    d) K₂SO₄

 

2. Which property of colloidal solution is independent of charge on the colloidal particles?

a) Electro-osmosis b)Coagulation c)Tyndall effect d)Electrophoresis

 

3. Which one of the followings forms micelles in aqueous solution above certain concentration?

a) Dodecyl trimethyl ammonium chloride

b) Glucose

c) Urea

d) Pyridinium chloride

 

4. The basic principle of Cottrell's precipitator is

a) Le-Chatelier's principle

b) peptisation

c) neutralisation of charge on colloidal particles

d) scattering of light

 

5. Assertion –Reason type questions:

In the following questions a statement of assertion followed by a statement of reason is given,Choose the correct answer from the following choices.

(a) Both assertion and reason are correct statements and the reason is a correct explanation for assertion.

(b) Both assertion and reason are correct but reason is not a correct explanation for assertion.

(c) Assertion is correct but reason is incorrect.

(d) Assertion is wrong but reason is correct.

 

i. Assertion : Adsorption decreases with increase in temperature

   Reason : Adsorption is generally temperature dependent

ii. Assertion: A catalyst is more effective in finely divided form.

    Reason: Finely divided form has more surface area.

 

6. Give an example of shape selective catalyst.

 

7. What is the basic difference between adsorption and absorption?

 

8. Why are finely divided substances more effective as an adsorbent?

 

9. Why is the adsorption phenomenon always exothermic?

 

10. What is meant by shape selective catalysis?

 

11. Out of AlCl₃ and NaCl, which is more effective in causing coagulation of a negative sol and why?

 

12. What is the difference between a colloidal solution and emulsion? What is the role of emulsifier in forming emulsion?

 

13. What are the characteristics of a solid catalyst?

 

14. What is activation of an adsorbent? How can it be achieved?

 

15. Differentiate between the following by giving examples.

a) Homogeneous and heterogeneous catalysis

b) Physical and chemical adsorption

c) Lyophobic and lyophilic colloids

 

16. What is the difference between multimolecular and macromolecular colloids?Give one example of each type. How associated colloids are different from these two types of colloids.

 

17. Explain how the phenomenon of adsorption finds application in each of the following processes:

a) Production of vacuum

b) Heterogeneous catalysis

c) Froth floatation process

 

18. Explain the following terms:

a) Tyndall effect

b) Electrophoresis

c) Dialysis

 

19. What happens when

a) Electric current is passed through a colloidal solution.

b) Solution of NaCl is added to a colloidal solution of Fe (OH)₃.

c) An emulsion is subjected to centrifugation.

Question. In case of adsorption,
a) a particle present in the bulk experience an unbalanced force
b) unbalanced forces are responsible for the interaction between adsorbate and adsorbent
c) extent of adsorption increases with increase of surface area per unit mass of adsorbent at a given temperature and pressure
d) All of the above

Answer: b

Question. An emulsions cannot be broken by
a) adding more amount of dispersion medium
b) freezing
c) adding emulsifying agent
d) Both (a) and (c)

Answer: d

Question. Which of the following is an example of the negatively charged sols?
a) FeCl₃ + NaOH 
b) FeCl₃ + hot water 
c) WhenAg⁺ is absorbed byAgI in solution ofAgNO₃ andKI
d) All of the above

Answer: a

Question. In Freundlich adsorption isotherm, the value of 1/n is
a) between 0 and 1 in all cases
b) between 2 and 4 in all cases
c) 1 in case of physical adsorption
d) 1 in case of chemisorption

Answer: a

Question. Which of the following is/are generally used for the removal of the coloured impurities from the solutions?
a) Charcoal
b) Silica gel
c) Both (a) and (b)
d) Anhyd. CaCl₂

Answer: a

Question. Which property of colloidal solutions is independent of charge on the colloidal particles?
a) Coagulation
b) Electrophoresis
c) Electroosmosis
d) Tyndall effect

Answer: d

Question. Which of the following are the examples of heterogeneous catalysis?
a) Haber’s process
b) Ostwald’s process
c) Oxidation of SO₂ into SO₃ in presence of Pt
d) All of the above

Answer: d

Question. The enzyme invertase converts the cane sugar into
a) glucose
b) fructose
c) glucose + fructose
d) None of the above

Answer: c

Question. Which of the following activity does not take place at the time of adsorption?
a) Residual attractive forces decreases
b) Surface energy decreases
c) Heat releases
d) Heat is absorbed

Answer: d

Question. Activators promoting catalytic actions are generally
a) metal ions
b) non-metal ions
c) metalloids ions
d) All of the above

Answer: a

Question. Lyophobic colloids are not stable because
a) they coagulate by heating them or with the addition of electrolytes
b) they coagulate by freezing them or with the addition of electrolytes
c) they do not coagulate by freezing themwith the electrolytes
d) they do not coagulate by heating themwith the electrolytes

Answer: a

Question. When pressure is low, the fraction of the surface covered during adsorption follows:
a) Zero order kinetics
b) First order kinetics
c) Second order kinetics
d) Fractional order kinetics

Answer: b

Question. Gold sols and sulphur sols are the examples of
a) multimolecular colloids
b) macromolecular colloids
c) associated colloids
d) All of the above

Answer: a

Question. The activity of a catalyst depends upon the strength of
a) chemisorption
b) physisorption
c) solution
d) None of the above

Answer: a

Question. Purification of the colloidal solution is carried out by
a) dialysis
b) electrodialysis
c) ultrafiltration
d) All of thesee

Answer: d

Question. Tyndall effect is observed only, when
a) the diameter of the dispersed particles is not much smaller than the wavelength of light used.
b) there is high difference between the refractive indices (μ ) of the dispersion medium and dispersed phase.
c) refractive indices (μ ) of both dispersed medium and dispersed phase are equal to each other.
d) Both (a) and (b)

Answer: d

Question. Which of the following is the most acceptable reason to explain the charge on sol particles?
a) Electron capture by sol particles during electrodispersion
b) Preferential adsorption of ions from solution
c) Formulation of electrical double layer
d) None of the above

Answer: b

Question. Smoke is precipitated by the
a) Cottrell precipitator
b) colloidal precipitator
c) natural precipitator
d) Planck’s precipitator

Answer: a

Question. The potential difference between the fixed layer and diffused layer of opposite charges in the colloidal system is known as
a) Zeta potential
b) gravitational potential
c) standard potential
d) ionic potential

Answer: a

Question. Which of the following substance acts as a catalyst for the following reaction?
2KClO₃→ 2KCl + 3O₂
a) MnO₂
b) O₂
c) HCl
d) All of these

Answer: a

Question. Lyophilic sols are more stable than lyophobic sols because
a) lyophobic sols are extensively solvated
b) lyophilic sols are extensively solvated
c) lyophilic sols are negatively charged
d) lyophilic sols are reversible in nature

Answer: b

Question. Which of the following processes is involved in Bredig’s arc method?
a) Only dispersion
b) Only condensation
c) Dispersion as well as condensation
d) Diffusion

Answer: c

Question. Butter and cream are the examples of
a) w/o type emulsion
b) o/w type emulsion
c) Both (a) and (b)
d) None of these

Answer: a

Question. Medicines are more effective in their colloidal form because
a) in such condition, these gets easily precipitated in the blood
b) in this state, these are more stable
c) in this state, they have large surface area and hence, get easily assimilated
d) All of the above

Answer: c

Please click on below link to download CBSE Class 12 Chemistry Surface Chemistry Worksheet Set B