Question

$H^{+}$ ion concentration of water does not change by adding :

• A. $C{H}_{3}COONa$
• B. $NaN{O}_3$
• C. $NaCN$
• D. $N{a}_{2}C{O}_3$

Answer 1

The correct option is B $NaN{O}_3$

$H^{+}$ ion concentration of water does not change by adding $NaN{O}_3$.

$NaN{O}_3$ is salt of strong acid ($HN{O}_3$) with strong base ($NaOH$). It is not hydrolyzed in aqueous solution and does not affect pH of the solution.

Pure water has $H^{+}$ ion concentration of ${10}^{-7}M$. When $NaN{O}_3$ is added to pure water, $H^{+}$ ion concentration remains at ${10}^{-7}M$.

$C{H}_3-COONa$, $NaCN$ and $N{a}_{2}C{O}_3$ .are salts of strong base and weak acid. In aqueous solution, anion will hydrolyse to from hydroxide ions. Hence, $H^{+}$ ion concentration of water decreases by adding $C{H}_3-COONa$, $NaCN$ or $N{a}_{2}C{O}_3$