Name two industrial process where heterogeneous catalysts are used.

Explanation

(i) In the manufacture of sulphuric acid by contact process `SO_3` is prepared by the action of `SO_2` and `O_2` in the presence of Pt or `V_2O_5` as a catalyst.
`2SO_2 + O_2 overset(Pt " or " V_2O_5)(to) 2SO_3`
(ii) In the Haber's process for the manufacture of ammonia, iron is used as a catalyst for the reaction between Hydrogen and Nitrogen.
`N_2 + 3H_2 overset(Fe)(to) 2NH_3`