Write any two characteristics of Chemisorption.
Why does physisorption decrease with the increase of temperature?
Why are powdered substances more effective adsorbents than their crystalline forms?
In Haber’s process, hydrogen is obtained by reacting methane with steam in presence of NiO as a catalyst. The process is known as steam reforming. Why is it necessary to remove CO when ammonia is obtained by Haber’s process?
Why is the ester hydrolysis slow in the beginning and becomes faster after some time?
What is the role of desorption in the process of catalysis.
What modification can you suggest in the Hardy Schulze law?
Why is it essential to wash the precipitate with water before estimating it quantitatively?
Distinguish between the meaning of the terms adsorption and absorption. give one example of each.
What is the difference between Physisorption and Chemisorption?
| Give reasons why a finely divided substance is more effective as an adsorbent?
What are the factors which influence the adsorption of a gas on a solid?
What is an adsorption isotherm? Describe Freundlich adsorption isotherm.
What do you understand by activation of adsorbent? How is it achieved?
What role does adsorption play in heterogeneous catalysis ?
Why is adsorption is always exothermic ?
How are the colloidal solutions classified on the basis of physical states of the dispersed phase and dispersion medium?
Discuss the effect of pressure and temperature on the adsorption of gases on solids?
What are lyophilic and lyophobic sols ? give one example of each type. Why are hydrophobic sols easily coagulated ?
What is the difference between multimolecular and macromolecular colloids ? Give one example of each .How are associated colloids different from this two types of colloids ?
What are enzymes? Write in brief the mechanism of enzyme catalysis ?
How are the colloids formed classified on the basis of
1) Physical states of components
2) Nature of dispersed phase
3) Interaction between Dispersed phase and dispersion medium.
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?
What are the emulsions ? What are their different types ? give one example of each type.
How do emulsifiers stabilize the emulsion? name two emulsifiers ?
Action of soap is due to emulsification and micelle formation. Comment ?
Give four examples of heterogeneous catalysis.
What do you mean by activity and selectivity of catalysts?
Describe some features of catalysis by zeolites.
What is shape selective catalysis?
Explain the following terms (i) Electrophoresis, (ii) Coagulation (iii) Dialysis (iv) Tyndall effect.
Give four uses of emulsions.
What are micelles? Give an example of micelles system.
Explain the terms with suitable examples.
(i) alcohol, (ii) aerosol (iii) Hydrosol.
Comment on the statement That “colloid is not a substance but a state of substance”.