Question

Why adsorption is a spontaneous process?

Answer 1

1. Adsorption is a surface phenomena in which the accumulation of substance occurs on the surface.
2. The two important components for adsorption are adsorbate and adsorbent.
3. Adsorbate is the substance that deposits on the surface of another substance. Example-${\mathrm{H}}_2,{\mathrm{N}}_2,{\mathrm{O}}_2$ gases.
4. The adsorbent is the surface on which adsorbate adsorbs. Example- Charcoal, Silica gel, Alumina.
5. The force of attraction between adsorbate and adsorbent is highly exothermic and releases heat.
6. The value of $∆\mathrm{H}$ is negative which means that adsorption is a spontaneous and exothermic process.