Assertion (A): The pH of a buffer solution containing equal moles of acetic acid and sodium acetate is 4.8 (`pK_(a)` of acetic acid is 4.8).
Reasons (R): The ionic product of water at `25^(circ)C is 10^(-14) mol^(2)L^(-2)`.
The correct answer is

Options

A. Both (A) and (R) are true and (R) is the correct explanation of (A)
B. Both (A) and (R) are true and (R) is not the correct explanation of (A)
C. (A) is true but (R) is not true
D. (A) is not true but (R) is true

Answer

B

Explanation

`pH = pK_(a) + "log"[sal t]/[acid]`
`since [CH_(3)COOH] = [CH_(3)COONa]`
`[p^(H) = P^(K_(a)) + "log"[CH_(3)COONa]/[CH_(3)COONa]] = P^(K_(a)) = 4.8`
`At 25^(circ)C, K_(w) = [H^(+)]xx[OH^(-)] = 1.0 xx 10^(-14) mol^(2)L^(-2)`
Hence, both (A) and (R ) are true and (R ) is not the correct explaination of (A)