Describe the industrial applications of hydrogen dependent on

Describe the industrial applications of hydrogen dependent on
(i) the heat liberated when its atoms are made to combine on the surface of a metal.
(ii) its effect on the unsaturated organic systems in the presence of a catalyst.
(iii) its ability to combine with nitrogen under specific conditions.

(i) Due to this property hydrogen is used in atomic hydrogen welding/cutting torch.
(ii) Due to this property hydrogen is used for the manufacture of vanaspati ghee from edible oils such as cotton-seed oil, soyabean oil, corn oil etc.

(iii) Due to this property dihydrogen is used for the manufacture of ammonia.