Question

Amongst the following statements regarding adsorption, those that are valid are:

(a) ΔH becomes less negative as adsorption proceeds.

(b) On a given adsorbent, ammonia is adsorbed more than nitrogen gas.

(c) On adsorption, the residual force acting along the surface of the adsorbent increases.

(d) With increase in temperature, the equilibrium concentration of adsorbate increases.

(1) (b) and (c)

(2) (c) and (d)

(3) (a) and (b)

(4) (d) and (a)

Answer 1

Ans. (3) (a) and (b)

Sol. (a) When gas is adsorbed on metal surface.

ΔH become less negative with progress of reaction.

(b) Gas with greater value of critical temperature (T_C) absorbed more. As T_C(NH₃) > T_C(N₂)

So NH₃ absorbed more than N₂.