Question

Consider the three solutions of $1M$ concentration.
(1) Sodium acetate $\left({CH}_{3}COONa\right)$
(2) Acetic acid$+$Sodium acetate
$({CH}_{3}COOH+{CH}_{3}COONa)$
(3) Acetic acid $\left({CH}_{3}COOH\right)$
The pH of these solutions will lie in the following sequence

• A. $3<2<1$
• B. $2<1<3$
• C. $1<2<3$
• D. $3<1<1$

Answer 1

Answer: (A)

$3<2<1$

$C{H}_{3}COONa$ is a salt of weak acid and strong base so it is basic in nature and $pH>7$.

$C{H}_{3}COOH+C{H}_{3}COONa$ will form an acidic buffer so it's $pH<7$ but greater than $pH$of $C{H}_{3}COOH$.

$C{H}_{3}COOH$ is a weak acid so its $pH<7$.

So $pH$ of these solutions will lie in following sequence:$3<2<1$