Chapter 18, Problem 124A

Interpretation Introduction

Interpretation:

The hydrogen ion concentration of highest and lowest $pH$ is to be calculated and compared.

Concept introduction:

pH gives the concentration of hydrogen ion in a solution.

It tells about acidity and basicity of a solution.

It is given by:

$\begin{array}{l}pH=-\log \left[H^{+}\right]\\ pOH=-\log \left[O{H}^{-}\right]\\ pH+pOH=14\\ \left[H^{+}\right]isconcentationofhydrogenions\\ \left[O{H}^{-}\right]isconcentationofhydroxylions\end{array}$

Answer to Problem 124A

$\begin{array}{l}\left[H^{+}\right](lowestpH)=8.3\times {10}^{-5}M\\ \left[H^{+}\right](highestpH)=1.4\times {10}^{-5}M\end{array}$

The rainwater with highest reading is 5.9 times more acid than lowest reading.

Explanation of Solution

Graph shows that highest $pH=4.85$

And lowest $pH=4.08approx$

Now, $\left[H^{+}\right]=anti\log (-pH)$

$\begin{array}{c}\left[H^{+}\right](lowestpH)=anti\log (-4.08)\\ =8.3\times {10}^{-5}M\end{array}$

$\begin{array}{c}\left[H^{+}\right](highestpH)=anti\log (-4.85)\\ =1.4\times {10}^{-5}M\end{array}$

Ratio $=\frac{8.3\times {10}^{-5}}{8.3\times {10}^{-5}}=5.9$

Thus rainwater with highest reading is 5.9 times more acid than lowest reading.

Conclusion

$\begin{array}{l}\left[H^{+}\right](lowestpH)=8.3\times {10}^{-5}M\\ \left[H^{+}\right](highestpH)=1.4\times {10}^{-5}M\end{array}$

The rainwater with highest reading is 5.9 times more acid than lowest reading.