Which of the following adsorption isotherms represents the adsorption of a gas by a solid involving physical adsorption ($P_s =$ saturation pressure)?

During the adsorption of krypton on activated charcoal at low temperature,which of the following thermodynamic conditions is true?

The critical temperatures of some gases are given. Which gas shows the least adsorption on a definite amount of charcoal?

Gas	Critical Temperature
$A$	$304 \ K$
$B$	$630 \ K$
$C$	$200 \ K$
$D$	$540 \ K$

$100 \ mL$ of $0.6 \ M$ acetic acid is shaken with $2 \ g$ activated carbon. The final concentration of the solution after adsorption is $0.5 \ M$. The amount of acetic acid adsorbed per gram of carbon is $... \ g$.

The adsorption of a gas on a solid surface follows the Freundlich adsorption isotherm. At $T(K)$,the gas pressure is $2 \ atm$. What is the value of $\frac{x}{m}$? (Given: $n=2$ and $k=$ constant)

The correct statement$(s)$ pertaining to the adsorption of a gas on a solid surface is (are):
$(A)$ Adsorption is always exothermic.
$(B)$ Physisorption may transform into chemisorption at high temperature.
$(C)$ Physisorption increases with increasing temperature but chemisorption decreases with increasing temperature.
$(D)$ Chemisorption is more exothermic than physisorption,however it is very slow due to higher energy of activation.