Question

If one litre of water contains ${10}^{-5}$ moles of $H^{+}$ ions at a certain temperature. Calculate the degree of ionization of water.

• A. $18\times {10}^{-9}$
• B. $3.6\times {10}^{-6}$
• C. $1.8\times {10}^{-10}$
• D. $1.8\times {10}^{-7}$

Answer 1

The correct option is D $1.8\times {10}^{-7}$

The dissociation taking place is,
$H_{2}O\left(l\right)\rightleftharpoons H^{+}(aq.)+O{H}^{-}(aq.)$
C 0 0
$C(1-\alpha )C\alpha C\alpha$

$C\alpha ={10}^{-5}M$

$C=\left[H_{2}O\right]=\frac{1000}{18}M$

Putting the values,

$\frac{1000}{18}\times \alpha ={10}^{-5}$

So,
$\alpha =18\times {10}^{-8}$

$\alpha =1.8\times {10}^{-7}$