Chapter 7, Problem 7.4E

(a)

Interpretation Introduction

Interpretation:

The concentration of $\text{A}$ after $5.0\text{h}$ has to be determined.

Concept Introduction:

According to the integrated rate law for the first order reaction, the concentration of reactant is the exponential function of time.  The two equations that represent the integrated rate law for the first order kinetics is shown below.

    $\begin{array}{c}\ln \frac{{\left[\text{A}\right]}_{\text{t}}}{{\left[\text{A}\right]}_0}=-k_{\text{r}}t\\ {\left[\text{A}\right]}_{\text{t}}={\left[\text{A}\right]}_0{\text{e}}^{-k_{\text{r}}t}\end{array}$

(b)

Interpretation Introduction

Interpretation:

The rate constant for the decomposition of $\text{B}$ at $\text{398}\text{K}$ has to be determined.

Concept Introduction:

Same as part (a).