Which of the following statements is not applicable to chemisorption?

Two statements are given below.
Statement-$I$: Adsorption of a gas on the surface of charcoal is primarily an exothermic reaction.
Statement-$II$: $A$ closed vessel contains $O_2, H_2, Cl_2, NH_3$ gases. Its pressure is $P \ atm$. About $1 \ g$ of charcoal is added to this vessel and after some time its pressure was found to be less than $P \ atm$.
The correct answer is:

Adsorption is multilayer in case of

Which one of the following is correct for the adsorption of a gas at a given temperature on a solid surface?

Identify the example of sorption from the following.

$A$ plot of $\log \left( \frac{x}{m} \right)$ vs $\log \, P$ for the adsorption of a gas on a solid gives a straight line with slope equal to