Chapter 15, Problem 128CP

The following data were collected in two studies of the reaction

$\text{2A}\text{+}\text{B}\to \text{C}\text{+}\text{D}$

where

$\text{Rate}=\frac{-\text{d[A]}}{\text{dt}}$

In experiment $1$ , ${\text{[B]}}_{\text{0}}=5.0\text{M}$ . In experiment $\text{2}$ , ${\text{[B]}}_{\text{0}}=10.0\text{M}$ .

1. Why is $\text{[B]}$ much greater than $\text{[A]}$?
2. Give the rate law and value for $\text{k}$ for this reaction.
3. Which of the following mechanisms could be correct for this reaction? Justify your choice.

1. $\text{A}\text{+}\text{B}\rightleftharpoons \text{E}$ (fast equilibrium)
   $\text{E}\text{+}\text{B}\to \text{C}\text{+}\text{D}$ (Slow)
2. $\text{A}\text{+}\text{B}\rightleftharpoons \text{E}$ (fast equilibrium)
   $\text{E}\text{+}\text{A}\to \text{C}\text{+}\text{D}$ (slow)
3. $\text{A}\text{+}\text{A}\to \text{E}$ (slow)
   $\text{E}\text{+}\text{B}\to \text{C}\text{+}\text{D}$ (fast)