Question

$p{K}_a$ of weak acid is 3.0. Effective range of a buffer of $HA$ and $A^{-}$ is about $pH$:

• A. $3$ to $4$
• B. $3$ to $6$
• C. $2$ to $3$
• D. $2$ to $4$

Answer 1

The correct option is D $2$ to $4$

Range of Buffer solution is $[pKa-1,pKa+1]$

$\therefore$ Ans is $[2,4]$ i.e., from $2$ or $4$