Chapter 19.4, Problem 31R

To determine

To calculate: The average rate of the reaction.

Answer to Problem 31R

The average rate of reaction is $4.7\times {10}^{-4}\text{M/s}$ .

Explanation of Solution

Given information:

The initial concentration is $0.030\text{0 mol/L}$

The final concentration is $0.0500\text{ mol/L}$

The time interval is 42.5

Formula used:

The average rate of reaction is calculated as,

  $\text{Average}\text{rate}=-\frac{\mathrm{\Delta }\mathrm{c}}{\mathrm{\Delta }\mathrm{t}}$

Where, $\text{Δc}$ is the change in concentration and $\text{Δt}$ is the time interval

By substituting the given values in the above formula then the average rate is calculated as,

  $\begin{array}{c}\text{Average}\text{rate}=-\frac{\mathrm{\Delta }\mathrm{c}}{\mathrm{\Delta }\mathrm{t}}\\ =-\frac{{\mathrm{c}}_{\text{initial}}-{\mathrm{c}}_{\mathrm{f}\mathrm{i}\mathrm{n}\mathrm{a}\mathrm{l}}}{42.5\sec }\\ =-\frac{\left(0.0300-0.0500\right)\text{g/mol}}{42.5\sec }\\ =0.00047\text{M/sec}\\ =4.7\times {10}^{-4}\text{M/s}\end{array}$

Conclusion:

Thus, the average rate is $4.7\times {10}^{-4}\text{M/s}$ .