Question

Assertion :An aqueous solution of ammonium acetate can act as a buffer. Reason: Acetic acid is a weak acid and ${NH}_{4}OH$ is a weak base.

• 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. Both Assertion and Reason are incorrect

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

Ammonium acetate solution is a buffer formed by a weak acid and a weak base. When an acid is added to the buffer, the acetate ion from the salt combine with $H_3{O}^{+}$ to form acetic acid.

${CH}_3{COO}^{-}+H_3{O}^{+}\rightleftharpoons {CH}_{3}COOH+H_{2}O$

When a base is added, the ammonium ion combine with ${OH}^{-}$ to form ammonium hydroxide.

${NH}_4^{+}+{OH}^{-}\rightleftharpoons {NH}_{4}OH$

Thus $pH$ is maintained constant.