Question

If the pH is 10, what is the concentration of hydroxide ion?

Answer 1

Answer : The correct option is, $10^{-4}M$

Explanation : Given,

pH = 10

First we have to calculate the pOH.

$pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-10=4$

Now we have to calculate the $OH^-$ concentration.

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

$4=-\log [OH^-]$

$[OH^-]=1.0\times 10^{-4}M$

Therefore, the $OH^-$ concentration is, $1.0\times 10^{-4}M$