Mechanism of a hypothetical reaction X 2 + Y 2 → 2 XY is given below: (i) X 2 → X + X fast (ii) X + Y 2 ⇌ XY…

Mechanism of a hypothetical reaction X2+Y22XY is given below:
(i) X2X+X fast
(ii) X+Y2XY+Y slow
(iii) X+YXY fast
The overall order of the reaction will be
  1. 1
  2. 2
  3. 0
  4. 1.5

Solution

The solution of this question is given by assuming step (i) to be reversible which is not given in question
Overall rate = Rate of slowest step (ii)
=kX Y2 ......(i)
K=rate constant of step (ii)
Assuming step (i) to be reversible, its equilibrium constant,
keq=X2X2     X=keq12 X212 .....(ii)
Put (ii) in (i)
Rate =kkeq12 X212 Y2
Overall order =12+1=32

Asked in: NEET 2017

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