Question

Consider the following mechanism. step 1: A+B C step 2: C+A → D equilibrium slow overall: 2A+B - D Determine the rate law for the overall reaction (where the overall rate constant is represented as k). rate=

Answer 1

rate depends on the slowest step

Here 2nd step is slowest.

So, rate law is:

rate = k2[C][A]

here C is an intermediate. It should be removed from rate law.

Using eqn 1:

kc = [C]/[A][B]

[C] = Kc[A][B]

Put this value in rate law expression:

rate = k2[C][A]

rate = k2Kc[A][B][A]

rate = k2Kc[A]^2[B]

Let k2Kc be k

so,

rate = k[A]^2[B]

Answer:

rate = k[A]^2[B]