Question

Mineral acids are stronger acids than carboxylic acids because :
(i) mineral acids are partially ionised
(ii) minerals acids are completely ionised
(iii) carboxylic acids are a partially ionised
(iv) carboxylic acids are completely ionised
Select the correct alternative.

• A. (i) and (ii)
• B. (ii) and (iii)
• C. (iii) and (iv)
• D. (i) and (iv)

Answer 1

The correct option is B (ii) and (iii)

Carboxylic acid, in which a $C$ atom is bonded to a $O$ atom by a double bond and to a hydroxyl group ($OH$) by a single bond. A fourth bond links the carbon atom to a $H$ atom. The carboxyl ($COOH$) group is so-named because of the carbonyl group ($C=O$) and a hydroxyl group.

Examples of common mineral acids are hydrochloric acid and sulphuric acid. A strong acid is completely ionised in aqueous solution and ionisation equilibria are not established, as complete ionisation occurs.

Example hydrogen chloride: $HCl\left(aq\right)\to H^{+}\left(aq\right)+C{l}^{-}\left(aq\right)$

A weak acid is one which is partially ionised in aqueous solution. for weak acids, ionisation equilibrium is established, as only partial ionisation occurs.

Example carbonic acid: $H_{2}C{O}_3\left(aq\right)$ $\to$ $2H^{+}\left(aq\right)$ $+{CO{}_3}^{2-}$