Which inert gas is used in chromatography?

Adsorption of a gas follows the Freundlich adsorption isotherm. In the given plot,$x$ is the mass of gas adsorbed on mass $m$ of the adsorbent at pressure $p$. $\frac{x}{m}$ is proportional to:

Which of the following represents the Freundlich adsorption isotherm equation?

Which forms multimolecular layers during adsorption?

Assertion : In chemisorption,adsorption first increases with temperature and then decreases.
Reason : Heat keeps on providing more and more activation energy.

Which of the following statements is not correct in respect of chemisorption?