Chapter 18.3, Problem 35SSC

Interpretation Introduction

Interpretation:

The $pH$ value of an acidic solution is always smaller than $pOH$ of same solution. Explain.

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 35SSC

For acidic solution,

$pH<7$

$\begin{array}{l}pH+pOH=14\\ pH=14-pOH\\ AspH<7\\ \therefore 14-pOH<7\\ Thisimplies\\ pOH>7\end{array}$

Explanation of Solution

The sum of $pHandpOH$ is $14$ and for acid, $pH<7$ therefore, $pOH>7$ or it can be said that the $pH$ value of an acidic solution is always smaller than $pOH$ of same solution.

Conclusion

The $pH$ value of an acidic solution is always smaller than $pOH$ of same solution.