In the adsorption of oxalic acid by activated charcoal, the activated charcoal is known as the

The gas which is adsorbed in minimum amount by the activated charcoal is

(Critical temperature of ${\mathrm{SO}}_{\mathrm{2}}: 430 \mathrm{K}, {\mathrm{Cl}}_{\mathrm{2}}: 417 \mathrm{K}, {\mathrm{NH}}_{\mathrm{3}}: 406 \mathrm{K} \mathrm{and} {\mathrm{N}}_{\mathrm{2}}: 126 \mathrm{K}$)