Question

The pOH of a solution is 10.75. What is the concentration of OH??? ions in the solution?

Answer 1

Answer: $[OH^-] =10^{-10.75}=1.778\times 10^{-11}M$

Explanation: pOH is defined as negative logarithm of hydroxide ions. More is the number of $[OH^-]$ ions , lesser is the pOH and vice versa.

pH + pOH = 14

$pOH=-log[OH^{-}$

$10.75=-log[OH^-]$

$[OH^-] =10^{(-10.75)}=1.778\times 10^{-11}M$

Answer 2

Answer : The concentration of the OH is, $1.778\times 10^{-11}M$

Solution : Given,

$pOH=10.75$

pH : It is defined as the negative logarithm of the hydronium ion concentration.

$pH=-\log [H^+]$    .........(1)

pOH : It is defined as the negative logarithm of the hydroxide ion concentration.

$pOH=-\log [OH^-]$    ........(2)

Now put the value of pOH in expression (2), we get the concentration of OH ion.

$10.75=-\log [OH^-]$

$[OH^-]=10^{-10.75}$

$[OH^-]=1.778\times 10^{-11}M$

Therefore, the concentration of the OH is, $1.778\times 10^{-11}M$