Chapter 16.4, Problem 16.4SC

Interpretation Introduction

Interpretation:

The $\text{pOH}$ of the rainwater should be calculated.

Concept Introduction:

The mathematical product of both ${\text{[H}}^{\text{+}}\text{]}$ and ${\text{[OH}}^{-}\text{]}$ concentrations are always constant known as ion product constant ( ${\text{K}}_{\text{w}}$ )

${\text{[H}}^{+}{\text{][OH}}^{-}\text{]=1}\times {\text{10}}^{-14}={\text{K}}_{\text{w}}$

To express the small number, p scale is used, which implies to take the log of a number. Since, the concentration of ${\text{[H}}^{+}\text{]}$ in aqueous solution is small, by using the p scale in the form of $\text{pH}$ scale, it is better way to represent acidity of solution.

Thus, $\text{pH}$ = ${\text{-log [H}}^{+}\text{]}$

The relation between $\text{pH}$ and $\text{pOH}$ can be derived from ${\text{K}}_{\text{w}}$.

$\text{pH+ pOH =14}$.