The volumes of gases ${\mathrm{H}}_2,{\mathrm{CH}}_4,{\mathrm{CO}}_2$, and ${\mathrm{NH}}_3$ adsorbed by $1\mathrm{gm}$ of charcoal at $288 \mathrm{K}$ are in the order.

• The adsorbed gas is directly proportional to their stability. Since ${\mathrm{NH}}_3$ has hydrogen bonding, it is the most stable. Other molecules give do not have hydrogen bond between them, thus we arrange them on the basis of their molecular mass. More the molecular mass, more is the volume of gases adsorbed at $288 K$.

Hence, the correct answer is option C) ${\mathrm{NH}}_3>{\mathrm{CO}}_2>{\mathrm{CH}}_4>{\mathrm{H}}_2$.