Question

Which acids are highly corrosive in nature?

• A. Acetic acid and oxalic acid
• B. Acetic acid and sulfuric acid
• C. Sulfuric acid and nitric acid
• D. Carbonic acid and nitric acid

Answer 1

The correct option is C

Sulfuric acid and nitric acid

The explanation for the correct option (C):

• The corrosiveness of an acid or base relates to how severely it destroys surfaces, particularly living tissue when they come into touch with it.
• Strong acids such as Hydrofluoric acid ($\mathrm{HF}$) have exceptionally low pH and are highly corrosive. Hence, extra attention needs to be given while handling since they eat through tissue and even bone.
• Strong acids are those which dissociate completely to produce Hydrogen ions (${\mathrm{H}}^{+}$) ions when dissolved in Water (${\mathrm{H}}_2\mathrm{O}$).
• Example: Sulfuric acid (${\mathrm{H}}_2{\mathrm{SO}}_4$) and Nitric acid (${\mathrm{HNO}}_3$) are strong acids. Hence, both the acids are highly corrosive in nature.

${\mathrm{H}}_2{\mathrm{SO}}_4\left(\mathrm{aq}\right)\to 2{\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{{\mathrm{SO}}_4^{2-}}^{}\left(\mathrm{aq}\right)$

${\mathrm{HNO}}_3\left(\mathrm{aq}\right)\to {\mathrm{H}}^{+}\left(\mathrm{aq}\right)+{\mathrm{NO}}_3^{-}\left(\mathrm{aq}\right)$

The explanation for the incorrect options:

• (A) Acetic acid (${\mathrm{CH}}_3\mathrm{COOH}$) and Oxalic acid (${\mathrm{C}}_2{\mathrm{H}}_2{\mathrm{O}}_4$) are weak acids, which partially ionize in an aqueous solution. Hence, they are not corrosive in nature.

$$\begin{gathered} {\mathrm{CH}}_3\mathrm{COOH}\left(\mathrm{aq}\right)\rightleftharpoons {\mathrm{CH}}_3{\mathrm{COO}}^{-}\left(\mathrm{aq}\right)+{\mathrm{H}}^{+}\left(\mathrm{aq}\right) \\ {\mathrm{C}}_2{\mathrm{H}}_2{\mathrm{O}}_4\left(\mathrm{aq}\right)\rightleftharpoons {\mathrm{HC}}_2{\mathrm{O}}_4^{-}\left(\mathrm{aq}\right)+{\mathrm{H}}^{+}\left(\mathrm{aq}\right) \end{gathered}$$

• (B) Acetic acid is a weak acid. Hence, it is not corrosive in nature.
• (D) Carbonic acid (${\mathrm{H}}_2{\mathrm{CO}}_3$) is a weak acid. Hence, it is not corrosive in nature.

Final Answer: Hence, option (C) is correct. Sulfuric acid and Nitric acid are highly corrosive in nature.