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

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

Which one of the following statements is not correct?

When $O_{2}$ is adsorbed on a metallic surface,electron transfer occurs from the metal to $O_{2}$. The $TRUE$ statement$(s)$ regarding this adsorption is(are)
$(A)$ $O_{2}$ is physisorbed
$(B)$ heat is released
$(C)$ occupancy of $\pi_{2p}^{*}$ of $O_{2}$ is increased
$(D)$ bond length of $O_{2}$ is increased

The volumes of gases $H_2, CH_4, CO_2$ and $NH_3$ adsorbed by $1 \ g$ of charcoal at $288 \ K$ are in the order:

If the adsorbate is held on a surface by weak Van der Waals forces,the adsorption process is called:

Assuming Langmuir monolayer adsorption,the volume of nitrogen gas adsorbed on a sample of silica gel at $STP$ is $1.30 \, cm^3 \, g^{-1}$. The area occupied by a nitrogen molecule is $0.16 \, nm^2$. The surface area of silica gel per gram is ......... $m^2 \, g^{-1}$.