Question

An acid buffer is obtained on mixing :

• A. $100\text{mL of}0.1MC{H}_{3}COOH\text{and}200\text{mL of}0.1MNaOH$
• B. $100\text{mL of}0.1MC{H}_{3}COOH\text{and}100\text{mL of}0.1MNaOH$
• C. $100\text{mL of}0.1MHCl\text{and}200\text{mL of}0.1MC{H}_{3}COONa$
• D. $100\text{mL of}0.1MHCl\text{and}200\text{mL of}0.1MNaCl$

Answer 1

The correct option is C $100\text{mL of}0.1MHCl\text{and}200\text{mL of}0.1MC{H}_{3}COONa$

A buffer solution is an aqueous solution consisting of a mixture of a weak acid and its conjugate base, or vice versa.

$HCl+C{H}_{3}COONa\to C{H}_{3}COOH+NaCl$
$10mmol20mmol--$
$-10mmol10mmol10mmol\left(\text{after reaction}\right)$

So, finaly we get mixture of
$C{H}_{3}COOH+C{H}_{3}COONa$ that will work like acidic buffer solution.

Hence, option (c) only act as acid buffer.