The process that does not occur at the interface of phases is :

1.  Crystallisation

2.  Heterogeneous catalysis

3.  Homogeneous catalysis

4.  Corrosion

 

 

The interface that cannot be obtained is 

1. Liquid-liquid

2. Solid-liquid

3. Liquid-gas

The term ‘sorption’ stands for.........

1.  Absorption

2.  Adsorption 

3.  Both absorption and adsorption

4.  Desorption

Extent of adsorption of adsorbate from the solution phase increases with:
1. Increase in amount of adsorbate in solution.
2. Decrease in surface area of adsorbent.
3.  Increase in temperature of solution.
4. Decrease in amount of adsorbate in solution.

Physical adsorption is not favoured by : 

1. High pressure.

2. Negative $∆$H

3. Higher critical temperature of adsorbate.

4. High temperature.

Extent of physisorption of a gas increases with ......

1. Increase in temperature.

2. Decrease in temperature.

3.  Decrease in surface area of adsorbent.

4.  Decrease in strength of van der Waals’ force. 

An emulsion cannot be broken by ............. and ................

1. Heating.

2. Adding more amount of dispersion medium.

3. Freezing.

4. Centrifugation

Physical adsorption of a gaseous species may change to chemical adsorption with ..........

1.  Decrease in temperature.

2.  Increase in temperature.

3.  Increase in surface area of adsorbent.

4.  Decrease in surface area of adsorbent.

In physisorption adsorbent does not show specificity for any particular gas because..........

1.  Involved van der Waals’ forces are universal.

2.  Gases involved behave like ideal gases.

3.  Enthalpy of adsorption is low.

4.  It is a reversible process.

Among the following options the example of absorption is :

1.  Water on silica gel.

2.  Water on calcium chloride.

3.  Hydrogen on finely divided nickel.

4.  Oxygen on metal surface.