Free NCERT Solutions For Class 12 Chemistry Chapter 5 : Surface Chemistry Free PDF Download

Intext Exercise

Question 1:
Write any two Characteristics of Chemisorption.

Question 2:
Why does physisorption decrease with the increase of temperature?

Question 3:
Why are powdered substances more effective adsorbents than their crystalline forms?

Question 7:
What modification can you suggest in the Hardy-Schulze law?

NCERT EXERCISE

Question 1:
Distinguish between the meaning of the terms adsorption and absorption. Give one example of each.

Question 2:
What is the difference between physisorption and chemisorption?

Question 4:
What are the factors which influence the adsorption of a gas on a solid?

Question 5:
What is an adsorption isotherm? Describe Freundlich adsorption isotherm.

Question 6:
What do you understand by activation of adsorbent? How is it achieved?

Question 7:
What role does adsorption play in heterogeneous catalysis?

Question 8:
Why is adsorption always exothermic?

Question 10:
Discuss the effect of pressure and temperature on the adsorption of gases on solids.

Question 11:
What are lyophilic and lyophobic sols? Give example of each type. Why are hydrophobic sols easily coagulated?

Question 12:
What is the difference between multimolecular and macromolecular colloids? Give one example of each. How are associated colloids different from these two types of colloids?

Question 14:
How are colloids classified on the basis of
(i) Physical states of components
(ii) Nature of dispersion medium and
(iii) Interaction between dispersed phase and dispersion medium?

Question 15:
Explain what is observed
(i) When a beam of light is passed through a colloidal sol.
(ii) An electrolyte, NaCl is added to hydrated ferric oxide sol
(iii) Electric current is passed through a colloidal sol?

Question 16:
What are emulsions? What are their different types? Give example of each type.

Question 17:
What is demulsification? Name two demulsiffiers.

Question 19:
Give four examples of heterogeneous catalysis.

Question 21:
Describe some features of catalysis by zeolites.

Question 22:
What is shape selective catalysis?

Question 24:
Give four uses emulsions.

Question 25:
What are micelles? Give an example of a micelle system.

Question 27:
Comment on the statement that colloid is not a substance but a state of substance”.