Question

The $P^H$ of ${10}^{-3}M$ mono acidic base, if it is $1\%$ ionised is:

• A. 5
• B. 8
• C. 3
• D. 9

Answer 1

The correct option is A 5

$HA\left(aq\right)\leftrightharpoons H^{+}\left(aq\right)+A^{-}\left(aq\right)$

$Percentionization=\frac{\left[H^{+}\right]}{\left[HA\right]}\times 100$

$1=\frac{\left[H^{+}\right]}{\left[{10}^{-3}\right]}\times 100$

$\left[H^{+}\right]=\frac{1\times {10}^{-3}}{100}$

$\left[H^{+}\right]=1\times {10}^{-5}M$

$pH=-\log \left[H^{+}\right]$

$pH=-\log [1\times {10}^{-5}]$

$pH=5$