Question

Assertion :The pH of an aqueous solution of acetic acid remains unchanged by the addition of sodium acetate. Reason: The ionisation of acetic acid is suppressed by the addition of sodium acetate.

• 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 correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

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

${CH}_{3}COOH\rightleftharpoons {CH}_3{COO}^{-}+H^{+}$

${CH}_{3}COONa\to {CH}_3{COO}^{-}+{Na}^{+}$

So, $H^{+}$ decreases on addition of acetate due to common on effect. So, $pH$ changes.

So, only the second statement is correct.

Option D is correct.