For the reaction `2NO(g) + H_(2)(g) rarr N_(2)O(g) + H_(2)O(g)`, at `900 K` following data are observed.
`{:("Initial pressure of NO (atm)","Initial pressure of" H_(2)o (atm),"Initial rate of pressure decrease" (atm min^(-1))),(0.150,0.40,0.020),(0.075,0.40,0.005),(0.150,0.20,0.010):}`
Find the order of reaction.

Options

A. `3`
B. `2`
C. `1`
D. `0`

Answer

A

Explanation

form experiments `I` and `II, [H_(2)]` is constant and `[NO]` is doubled. Then rate becomes `4` times.
So order of reaction w.r.t. `(NO) = 2`.
form experiments `I` and `III, [NO]` is constant, and `[H_(2)]` is doubled then rate becomes `2` times. So order of reaction w.r.t. `(H_(2)) = 1`.
Total order `= 3`.
Hence answer (a) is correct.