Question

In a solution the concentration of [OH-] ions is 1×10^-12 mol/l it's pH is​

Answer 1

$\mathcal{\gray{\underbrace{\blue{GIVEN:-}}}}$

✍️ In a solution,

• $\rm{\green{[OH^{-}]\:=\:1\times{10}^{-12}\:mol.L^{-1}\:}}$

$\mathcal{\gray{\underbrace{\blue{TO\: FIND:-}}}}$

• It's pH .

$\mathcal{\gray{\underbrace{\blue{SOLUTION:-}}}}$

We have know that,

$\pink\checkmark\:\rm{\purple{\boxed{\red{pOH\:=\:-\:\log\:[OH^{-}]\:}}}}$

$\rm{\implies\:pOH\:=\:-\log[1\times{10}^{-12}]\:}$

$\rm{\implies\:pOH\:=\:-\log[{10}^{-12}]\:}$

$\rm{\implies\:pOH\:=\:-\:(-12)\:\log{10}\:}$

• log (10) = 1

$\rm{\implies\:pH\:=\:12\times{1}\:}$

$\rm\red{\implies\:pOH\:=\:12\:}$

✍️ We have know that,

• pH + pOH = 14

$\rm{\implies\:pH\:=\:14\:-\:pOH\:}$

$\rm{\implies\:pH\:=\:14\:-\:12\:}$

$\rm\green{\implies\:pH\:=\:2\:}$

________________________________

$\rm{\pink{\therefore}}$ The pH of the solution is “2” .