How is nitric acid prepared by Ostwald's process ?

Explanation

Preparation of nitric acid by Ostwald's process
(a) `4NH_(3(g))+5O_(2(g)) overset(Pt//Rh."gauge catalyst")underset(500K, 9"bar") to 4NO_((g))+6H_(2)O_((g))`
(b) `2NO_((g))+O_(2_(g)) hArr 2NO_(2(g))`
`2NO_(2(g))+H_(2)O_((g)) to 2HO_(3(1))+NO_((g))`