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Adsorption is multilayer in case of a)Physical adsorption b)Chemisorption c)In both d)Non of these

1. The forces operating in these are weak vander Waal’s forces..
2. The heat of adsorption are low i.e. about 20 – 40 kJ mol-1
3. It forms multi molecular layer.
4. The process is reversible.
5. It is not specific in nature i.e. all gases are adsorbed on all solids to some extent
6. It does not require any activation energy.
7. No compound formation takes place in these cases.
8. This type of adsorption decreases with increase of temperature.
9. The amount of the gas adsorbed is related to the ease of liquefaction of the gas.

1. The forces operating in these cases are similar to those of a chemical bond
2. The heat of adsorption are high i.e. about 40 – 400 kJ mol-1
3. It forms unimolecular layer.
4. The process is irreversible. Efforts to free the adsorbed gas give some definite compound.
5. Surface compounds are formed.
6. It is specific in nature and occurs only when there is some possibility of compound formation between the gas being adsorbed and the solid adsorbent.
7. It requires any activation energy.
8.  This type of adsorption first increases with increase of temperature. The effect is called activated adsorption.
9. There is no such correlation exists.