Unit : 5

Surface chemistry

M.M.20

1. Out of CO and NH₃ which is adsorbed on activated charcoal to large extent and why?                   2

 

2. Define : (i) Gels (ii) Brownian movement 2

 

3. Explain and describe what happens when :             3

• An electric current is passed through a colloidal solution.
• FeCl₃ is mixed with freshly prepared Fe(OH)₃
• Light is passed through a colloidal solution.

 

4. Differentiate between chemisorption & physisorptin.             3

 

5. Explain Langmuir adsorption isotherm. 2

 

6. Account for the following: 2

(i) A delta is formed at a point where river enters the sea.

(ii) As₂S₃ sol posses negative charge.

 

7. Explain activity and selectivity of a catalyst.             2

 

8. Explain Bredig’s Arc method.                                                                                                                  2

 

9. Give an example of water in oil type of emulsion. What type of emulsifier can be used for such emulsions?                                                                                                                                                 2