Question

The concentration of $\left[H^{+}\right]$ and ${\left[OH\right]}^{-}$ in a 0.1 M aqueous solution of 2% ionised weak monobasic acid is $[ionicproductofwater=1\times {10}^{-14}]$

• A. $0.02\times {10}^{-3}$ 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

$2$% ionisation= $\frac{\left[H^{+}\right]}{\left[Acid\right]}\times 100$

$\Rightarrow \left[H^{+}\right]=2\times 0.1\times {10}^{-2}$

$=2\times {10}^{-3}M$

$\left[H^{+}\right]\left[O{H}^{-}\right]={10}^{-14}$

$\therefore \left[O{H}^{-}\right]=\frac{{10}^{-14}}{\left[H^{+}\right]}=\frac{{10}^{-14}}{2\times {10}^{-3}}=5\times {10}^{-12}M$