S. No.

 

Point of difference

 

Physiosorption

 

Chemisorption

(i)

Specificity

This is not specific in nature.

This is highly specific in nature.

(ii)

Temperature dependence

Low temperature is favourable for physiosorption. It decreases with increase in temperature.

High temperature is favourable for chemisorption. It increases with the increase in temperature.

(iii)

Reversibility

This is reversible in nature.

This is irreversible in nature.

(iv)

Enthalpy change

Enthalpy of adsorption is low.

Enthalpy of adsorption is high.

 
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S. No.

 

Point of difference

 

Physiosorption

 

Chemisorption

(i)

Specificity

This is not specific in nature.

This is highly specific in nature.

(ii)

Temperature dependence

Low temperature is favourable for physiosorption. It decreases with increase in temperature.

High temperature is favourable for chemisorption. It increases with the increase in temperature.

(iii)

Reversibility

This is reversible in nature.

This is irreversible in nature.

(iv)

Enthalpy change

Enthalpy of adsorption is low.

Enthalpy of adsorption is high.

 
" />

          

S. No.

 

Point of difference

 

Physiosorption

 

Chemisorption

(i)

Specificity

This is not specific in nature.

This is highly specific in nature.

(ii)

Temperature dependence

Low temperature is favourable for physiosorption. It decreases with increase in temperature.

High temperature is favourable for chemisorption. It increases with the increase in temperature.

(iii)

Reversibility

This is reversible in nature.

This is irreversible in nature.

(iv)

Enthalpy change

Enthalpy of adsorption is low.

Enthalpy of adsorption is high.

 
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Surface Chemistry

Surface Chemistry

Question

Write three distinct features of chemisorptions which are not found in physisorptions.

Answer

Chemisorption is a kind of adsorption which involves a chemical reaction between the surface and the adsorbate.

Physisorption, also called physical adsorption, is a process in which the electronic structure of the atom or molecule is barely perturbed upon adsorption.

 

          

S. No.

 

Point of difference

 

Physiosorption

 

Chemisorption

(i)

Specificity

This is not specific in nature.

This is highly specific in nature.

(ii)

Temperature dependence

Low temperature is favourable for physiosorption. It decreases with increase in temperature.

High temperature is favourable for chemisorption. It increases with the increase in temperature.

(iii)

Reversibility

This is reversible in nature.

This is irreversible in nature.

(iv)

Enthalpy change

Enthalpy of adsorption is low.

Enthalpy of adsorption is high.

 

More Chapters from Surface Chemistry