What is the role of desorption in the process of catalysis?

The addition of soap in water:

$CH_4$ is adsorbed on $1 \ g$ charcoal at $0^{\circ} C$ following the Freundlich adsorption isotherm. $10.0 \ mL$ of $CH_4$ is adsorbed at $100 \ mm$ of $Hg$,whereas $15.0 \ mL$ is adsorbed at $200 \ mm$ of $Hg$. The volume of $CH_4$ adsorbed at $300 \ mm$ of $Hg$ is $10^x \ mL$. The value of $x$ is $....\times 10^{-2}$ (Nearest integer). [Use $\log_{10} 2=0.3010, \log_{10} 3=0.4771$]

Which of the following statements is not applicable to chemisorption?

In an adsorption experiment, a graph between $\log (x/m)$ vs $\log P$ was found to be linear with a slope of $45^{\circ}$. The intercept on the $\log (x/m)$ axis was found to be $0.3$. The amount of the gas adsorbed per gram of charcoal under a pressure of $1 \ atm$ is:

Write any two characteristics of chemisorption.