What is the pH of a solution whose H_3O^+ concentration is 1*10^-9?

Mar 24, 2018

9

Explanation:

pH of an acid is given by $- \log \left[{H}_{3} O\right]$

Where $\left[{H}_{3} O\right]$ is concentration of $\left[{H}_{3} O\right]$ ions

So, pH is $- \log \left({10}^{-} 9\right)$

$= - \left(- 9\right)$

$= 9$

Note: The logarithm is to the base 10.