Question

The concentration of $\left[H^{+}\right]$ and $\left[{OH}^{-}\right]$ of a $0.1M$ aqueous solution of $2$% ionised weak acid is:(ionic product of water$=1.0\times {10}^{-14}$)

• A. $0.2\times {10}^{-3}M$ and $5\times {10}^{-11}M$
• B. $1\times {10}^{-3}M$ and $3\times {10}^{-11}M$
• C. $2\times {10}^{-3}M$ and $5\times {10}^{-12}M$
• D. $3\times {10}^{-2}M$ and $4\times {10}^{-13}M$

Answer 1

The correct option is C $2\times {10}^{-3}M$ and $5\times {10}^{-12}M$

$\left[H^{+}\right]=C\times \alpha =0.1\times 0.02=2\times {10}^{-3}$
$\left[{OH}^{-}\right]=\frac{K_w}{\left[H^{+}\right]}=5\times {10}^{-12}$