Question

What is the $pOH$ of a solution containing hydrogen ion concentration of $1\times {10}^{-8}M?$

• A. 7.04
• B. 0.8
• C. 8
• D. None of the above

Answer 1

The correct option is A 7.04

Here $\left[H^{+}\right]$ comes from water:
Total concentration of $\left[H^{+}\right]={10}^{-8}+{10}^{-7}$
For calculating pH we have to find pH first:
$RememberpH=-lo{g}_{10}\left[H^{+}\right]$

$pH=-lo{g}_{10}[{10}^{-7}+{10}^{-8}]=6.96$

$Weknow:pH+pOH=146.96+pOH=14\Rightarrow pOH=14-6.96=7.04pOH=7.04$