Question

Following mechanism has been proposed for a reaction,
$2A+B\to D+E$
$A+B\to C+D$ (Slow)
$A+C\to E$ (Fast)
The rate law expression for the reaction is:

• A. $r=K\left[A{]}^2\right[B]$
• B. $r=K\left[A\right]\left[B\right]$
• C. $r=K[A{]}^2$
• D. $r=K\left[A\right]\left[C\right]$

Answer 1

The correct option is B $r=K\left[A\right]\left[B\right]$

As we know,
slowest step is the rate determining step so
$Rate=K\left[A\right]\left[B\right]$