Question

Which statement is/are correct?

i) Physical adsorption is due to Van der Waal's forces

ii) Physical adsorption decreases at high temperature

iii) Physical adsorption is irreversible

iv) Enthalpy for a chemical adsorption is generally lesser than that of physical adsorption

• A. i, ii &iv
• B. i, ii & iii
• C. i, ii
• D. i&iv

Answer 1

The correct option is C

i, ii

Physisorption- The process is reversible i.e. desorption of the gas occurs by increasing the temperature or decreasing the pressure.

It takes place by the help of non-covalent attraction between adsorbate and adsorbent making the process reversible.

&enthalpy for a chemical adsorption is higher than that of physical adsorption