What is catalysis ? How is catalysis classified ? Give two examples for each type of catalysis.

Explanation

Catalysis : A substance which alters the rate of a chemical reaction without itself being consumed in the process, is called a catalyst.
The action of catalyst in altering the rate of a chemical reaction is called catalysts.
Yes of catalysis : Catalysis is classified into two types as
a) Homogeneous catalysis and
b) Heterogeneous catalysis.
Homogeneous catalysts : The catalytic process in which the catalyst is present in the same phase as that of reactants, is known as homogeneous catalysis.
a) `2SO_(2)(g) + O_(2)(g) overset(NO(g))to 2SO_(3)` [Lead chamber process].
b) `CH_(3)CHO (g) overset(I_(2)(g))to CH_(4)(g) + CO(g)`
Heterogeneous catalysis : The catalytic process in which the catalyst is present in a phase different from that of reactarts is known as heterogeneous catalysis.
Eg. : a) `2SO_(2(g)) + O_(2)(g) underset(V_(2)O_(5)(S))overset(Pt(S))to 2SO_(3(g))`
b) `N_(2(g)) + 3H_(2(g)) overset(Fe(s)) to 2NH_(3(g))` [Haber's process]