Question

For the reaction 2NO (g) + H₂(g)  —> N₂O (g) + H₂O (g), at 900 K. following data are observed.

Initial pressure of NO (atm)	Initial pressure of H2 (atm)	Rate
0.15	0.40	0.02
0.075	0.40	0.005
0.150	0.02	0.10

Find out the rate law and order of reaction-

(a) k [PNO₂]² [PH₂]¹,3

(b)  k [PNO₂]² [PH₂]¹,2

(c)  k [PNO₂]² [PH₂]¹,1

(d)  k [PNO₂]² [PH₂]¹,0

Answer 1

Correct Option (a) k [PNO₂]² [PH₂]¹,3

Explanation:

 Rate law equation in terms of pressure is

Rate = k [PNO₂]^m [PH₂]ⁿ

Substituting the given data in rate law equation we get,

(i) 0.02 = (0.15)^m [0.4]

(ii) 0.005 = (0.075)^m [0.4]ⁿ