# The volume of gases $H_2, \;CH_4, \;CO_2$ and $NH_3$ absorbed by 1 gm of activated charcoal at 298 K are in the order:

(a) $H_2>CH_4> CO_2>NH_3$

(b) $CH_4>CO_2>NH_3>H_2$

(c) $CO_2>NH_3>H_2>CH_4$

(d) $NH_3>CO_2>CH_4>H_2$

Answer: $NH_3>CO_2>CH_4>H_2$

A gas which is easy to liquify is most adsorbed. Thus, the order of ease of liquification, is the order of extent of adsorption.
$NH_3>CO_2>CH_4>H_2$