The volumes of gases H₂, CH₄, CO₂ and NH₃ adsorbed by one gram of charcoal at 288 K are in the order

The amount of gas adsorbed by a solid depends on the nature of the gas. In general, easily liquefiable gases having higher critical temperatures and are easily adsorbed because they have strong van der Waal's forces.

The increasing order of critical temperature is:

NH₃ > CO₂ > CH₄ > H₂

The volume of gases adsorbed by 1g of charcoal at 288K are in the order: 

NH₃ > CO₂ > CH₄ > H₂