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Questions
What is the difference between physisorption and chemisorption?
Difference between physisorption and chemisorption. Give one example.
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Solution
| Physisorption | Chemisorption | |
| 1 | In this type of adsorption, the adsorbate is attached to the surface of the adsorbent with weak van der Waal’s forces of attraction. | In this type of adsorption, strong chemical bonds are formed between the adsorbate and the surface of the adsorbent. |
| 2 | No new compound is formed in the process. | New compounds are formed at the surface of the adsorbent. |
| 3 | It is generally found to be reversible in nature. | It is usually irreversible in nature. |
| 4 | Enthalpy of adsorption is low as weak van der Waal’s forces of attraction are involved. The values lie in the range of 20-40 kJ mol−1. | Enthalpy of adsorption is high as chemical bonds are formed. The values lie in the range of 40-400 kJ mol−1. |
| 5 | It is favoured by low-temperature conditions. | It is favoured by high-temperature conditions |
| 6 | It is an example of multi-layer adsorption | It is an example of mono-layer adsorption. |
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