Question

Acetic acid (${\text{CH}}_3\text{COOH}$) is a weak acid because:

• A. it is formed by reaction between a weak oxide and water.
• B. it gets partially ionised in water.
• C. it is produced slowly from vinegar.
• D. it contains only four hydrogen atoms.

Answer 1

The correct option is B

it gets partially ionised in water.

Acetic acid (${\text{CH}}_3\text{COOH}$) ionises partially in water, hence, it is a weak acid. In other words, molecules of a weak acid ionises partially into corresponding ions, and the rest remain as simple acid molecules in water. The dissociation occurs as follows:

${\text{CH}}_3\text{COOH}\text{(aq)}\leftrightharpoons {\text{CH}}_3{\text{COO}}^{-}\text{(aq)}+{\text{H}}^{+}\text{(aq)}$