Question

The [OH-] of an aqueous solution is 6.4 x 10-5 M. What is the [H3O+]?

Answer 1

Answer: The $[H_3O^+]$ is $1.55\times 10^{-10}M$

Explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pOH is calculated by taking negative logarithm of hydroxide ion concentration.

$pOH=-\log [OH^-]$

Putting in the values:

$pOH=-\log[6.4\times 10^{-5}]$

$pOH=4.19$

$pH+pOH=14$

$pH=9.81$

$9.81=-\log [H_3O^+]$

$[H_3O^+]=1.55\times 10^{-10}$

Thus the $[H_3O^+]$ is $1.55\times 10^{-10}M$