JEE Main20202 Sep 2020Evening ShiftChemistrySurface ChemistryActual
Amongst the following statements regarding adsorption, those that are valid are: (a) Δ H 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.
Options
- A(d) and (a)
- B(b) and (c)
- C(a) and (b)
- D(c) and (d)
Correct answer
C. (a) and (b)
Step-by-step solution
(a) When gas is adsorbed on metal surface. Δ H become less negative with progress of reaction because number of active sites decreases. (b) Gas with greater value of critical temperature T C absorbed more. As T C NH 3 > T C N 2 So NH 3 absorbed more than N 2 . Statement (c) is wrong because residual forces decrease as adsorption proceeds further. Statement (d) is also wrong because temperature opposes extent of adsorption.