Q.What are the factors which influence the adsorption of a gas on a solid?

Step 1 – Nature of the gas. Gases that are more easily liquefiable (higher critical temperature) have stronger van der Waals forces and are adsorbed to a greater extent. Order of adsorption on charcoal: $SO_2 > CH_4 > H_2$; and $NH_3, HCl, Cl_2, CO_2$ are adsorbed more than $N_2, O_2, H_2$.

Step 2 – Nature and surface area of the adsorbent. The same gas is adsorbed to different extents by different solids; finely divided/porous solids with large surface area (charcoal, silica gel) adsorb more.

Step 3 – Temperature. Adsorption is exothermic, so physisorption decreases with rise in temperature; chemisorption may first increase. …

List the standard controlling variables: property of the gas (critical temperature/ease of liquefaction), property of the solid (surface area), and the oper …

• Omitting the gas's ease of liquefaction (critical temperature), a key factor. …