Physisorption | Chemisorption |
1. Physisorption is non- specific in nature due to Van der Waal's forces | 1. Chemisorption is highly specific in nature due chemical bond between adsorbate and adsorbent |
2. On increasing temperature chemisorption increases. | 2. Physisorption decreases with temperature |
3.Physisorption is reversible in nature | 3. Chemisorption is irreversible in nature |
4. In case of physisorption enthalpy change is small. For example, 20-40 kJ mol–1 (approx) | 4. In case of chemisorption enthalpy change is high. For example, 40-400 kJ mol–1 (approx) |