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

Reason: Chemical adsorption requires some activation energy.

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 : 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: 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.