Question

A sulphuric acid solution has $pH=3$. Its normality is:

• A. ${10}^{-3}$
• B. $5\times {10}^{-3}$
• C. $5\times {10}^{-4}$
• D. ${10}^{-2}$

Answer 1

The correct option is A ${10}^{-3}$

$pH=3$

$pH=-lo{g}_{10}\left[H^{+}\right]$

$\left[H^{+}\right]=1\times {10}^{-3}mol/L$

$H_2{SO}_4⟶2H^{+}+{SO}_4^{2-}$

$\left[H_2{SO}_4\right]=\frac{1\times {10}^{-3}}{2}=\frac{1}{2000}M$

$N=2M\left(for{H}_2{SO}_4\right)$

Normality $=\frac{2}{2000}=\frac{1}{1000}N={10}^{-3}N$

Hence, option A is correct.