2H2(g) + 2NO(g) → N2(g) + 2H2O(g) is given by rate = k[H2][NO]^2.

Question

The rate law for the reaction,

2H_2(g) + 2NO_(g) → N_2(g) + 2H₂O_(g) is given by rate = k[H₂][NO]². 

The reaction occurs in the following steps :

(i) H₂ + 2NO → N₂O + H₂O

(ii) N₂O + H₂ → N₂+ H₂O

What is the role of N₂O in the mechanism? 

Identify the slow step.

Answer 1

(a) N₂O is the reaction intermediate since it is formed in the first step and removed in the second step.

(b) By rate law, 

Rate = k [H₂][NO]². 

Since the first step involves the substances H₂ and NO, it is the slow and rate-determining step.