In an adsorption experiment, a graph between log(x/m) versus log P was found to be linear with a slope of 45$°$. The intercept on the y-axis was found to be 0.3. What will be the value of x/m at a pressure of 3 atm for the Freundlich adsorption isotherm when 1/n remains constant?

[Antilog 0.3 = 2]

1.  2

2.  4

3.  6

4.  5

Water vapours can be both adsorbed and absorbed by respectively ?

1. Silica gel and ${\mathrm{CaCl}}_2$

2. Chalk and ${\mathrm{CaCl}}_2$

3. ${\mathrm{CaCl}}_2$ and Silica gel

4. ${\mathrm{CaCl}}_2$ and Chalk

The decomposition of phosphine (PH₃) on tungsten at low pressure is a first-order reaction. It is because the:

1. rate is proportional to the surface coverage

2. rate is inversely proportional to the surface coverage

3. rate is independent of the surface coverage

4. rate of decomposition is very slow

Colloids can be prepared by 

1. Tyndall Effect                      

2.  Electrophoresis

3.  Dialysis                             

4.  Peptization

Assertion: Lowering of temperature, increases the rate of physisorption.

Reason: Adsorption increases with an increase in temperature.

1. Both assertion and reason are true and the reason is the correct explanation of the assertion.
2. Both assertion and reason are true but the reason is not the correct explanation of the assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

Assertion : The addition of ferric hydroxide sol to arsenic sulphide sol results in the precipitation

                   of both.

Reson : The colloidal particles in ferric hydroxide carry positive charge, whereas those in arsenic

             sulphide sol carry negative charge.

Assertion : Catalyst in general, in the form of finely divided powder.

Reason : Finer is the particle of a solid, greater is its surface area.

Assertion: Physical and chemical adsorption respond differently to a rise in temperature.

Reason: Chemical adsorption requires some activation energy.