The following mechanism has been proposed for the reaction of NO with Br2

Chemical Kinetics

The following mechanism has been proposed for the reaction of NO with Br2 to form NOBr.

NO(g) + Br2(g) ↔ NOBr2(g)

NOBr2(g) + NO(g) → 2NOBr(g)

If the second step is the rate determining step, the order of the reaction with respect to NO(g) is

  1. 0
  2. 1
  3. 2
  4. 3

Answer

NO(g) + Br2(g) → NOBr2(g)

NOBr2(g) + NO(g) → 2NOBr(g) [RDS]

Rate of the reaction (r) = K[NOBr2][NO]

Where [NOBr2] = Kc[NO][Br2]

r = K’[NO]2[Br2]

The order of the reaction with respect to NO(g) = 2

The correct option is C.