Question

Assertion :When sodium chloride is dissolved in water, both cation and anion undergo hydrolysis. Reason: The solution has pH$=7$ at ${25}^{o}C.$

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is incorrect but Reason is correct
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is incorrect but Reason is correct

Consider the equation :-
$N{a}^{+}C{l}^{-}\left(s\right)+H_{2}O\left(l\right)\to N{a}^{+}\left(aq\right)+C{l}^{-}\left(aq\right)$

In this equation, water hydrates the sodium and chloride ions to produce hydrated ions $N{a}^{+}\left(aq\right)$ and $C{l}^{-}\left(aq\right)$.

Here neither cation nor anion undergoes hydrolysis because this salt neither do have weak acids or weak bases as to have conjugate acid of weak base or conjugate base of weak acids.

The solution, therefore, is neutral in nature and must have pH value 7 at temp. ${25}^{0}C$.

Option C is correct.