Assertion (A): The `pH` of an aqueous solution of `CH_(3)COOH` remains unchanged on the addition of `CH_(3)COONa`.
Reason (R) : The `pH` of an aqueous solution of `CH_(3)COOH` remains unchanged on the addition of `CH_(3)COONa`.
Reason (R) : The ionisation of `CH_(3)COOH` is supressed by the addition of `CH_(3)COONa`.

Options

A. If both (A) and (R) are correc, and (R) is the correct explanation of (A).
B. If both (A) and (R) are correct but (R) is not the correct explanation of (A).
C. If (A) is correct, but (R) is incorrect.
D. If (A) is incorrect, but (R) is correct.

Answer

D

Explanation

`(A)` is wrong. It forms acidic buffer and this `pH` changes. `(R)` is correct. Due to common ion `(CH_(3)COO^(Theta))`, ionisation of `CH_(3)COOH` is supressed.