During the adsorption of a gas on a solid at low temperature,which of the following thermodynamic conditions is correct?

Why is it important to have a clean surface in surface studies?

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:

$A$ plot of $\log (x/m)$ versus $\log p$ for the adsorption of a gas on a solid gives a straight line with slope equal to

If $x$ amount of gas is adsorbed on $m$ amount of adsorbent at pressure $p$,the Freundlich adsorption isotherm plot gives a straight line for which of the following?

Assertion $(A)$: Adsorption is an exothermic process.
Reason $(R)$: Physisorption of a gas on a solid surface is normally reversible.