How does chemisorption change with an increase in temperature?

What should be taken on the $Y$-axis in the Freundlich adsorption isotherm plot to obtain a straight line?

Which among the following is true for chemisorption?

Which of the following statements is $NOT$ applicable to chemisorption?

During the process of adsorption,

$2.0 \ g$ of activated charcoal is added to $100 \ mL$ of $0.5 \ M$ acetic acid (molar mass $60 \ g \ mol^{-1}$),shaken well and filtered. The concentration of the solution is reduced to $0.4 \ M$. How many grams of acetic acid is adsorbed on charcoal per gram?