Which of the following is a buffer solution?

Options

A. A solution of `KC1` and `KOH`
B. A solution of `CH_(3)COONH_(4)`
C. A solution of `K_(2)SO_(4)` and `NH_(4)OH`
D. A solution of `PhCOOK` nad `PhCOOH`

Answer

D

Explanation

a. Mixture of salt of `S_(A)//S_(B)+S_(B)`.
b. Salt of `W_(A)//W_(B)`.
c. Mixture of salt of `S_(A)//S_(B)+W_(B)`.
d. Mixture of salt of `W_(B)//S_(B) +W_(A)` (Buffer)