Question

One liter of solution contains ${10}^{-5}$ moles of $H^{+}$ ions at ${25}^{o}C$.Percentage ionisation of water in solution is:

• A. $1.8\times {10}^{-7}\%$
• B. $1.8\times {10}^{-5}\%$
• C. $3.6\times {10}^{-9}\%$
• D. $1.8\times {10}^{-11}\%$

Answer 1

The correct option is B $1.8\times {10}^{-5}\%$

Molarity of water= $55.5$ mole

$H_{2}O\rightleftharpoons H^{+}+O{H}^{-}$

Let $x$ be the degree of dissociation

Then $55.5x={10}^{-5}$

$\Rightarrow x=1.8\times {10}^{-7}$

% $x=1.8\times {10}^{-7}\times 100=1.8\times {10}^{-5}$