Question

Which one of the following is a strong electrolyte?

• A. Sulphuric Acid
• B. Acetic Acid
• C. Carbonic Acid
• D. Phosphoric Acid

Answer 1

The correct option is A

Sulphuric Acid

Explanation for correct option

(A) Sulfuric Acid

• Electrolytes are substances that, when dissolved in water, separate into cations (positively charged) and anions (having a negative charge).
• However, there are two types of electrolytes found in nature: weak electrolytes and strong electrolytes.
• Weak electrolytes are those that do not completely dissociate into cations and anions when dissolved in an aqueous solution.
• Strong electrolytes are those that dissociate entirely and readily when dissolved in an aqueous solution.

Sulfuric Acid

• Sulfuric acid $\left({\mathrm{H}}_2{\mathrm{SO}}_4\right)$ dissociates completely and readily when dissolved in an aqueous solution.
• The reaction is as follows:

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

• It is a strong electrolyte.

Explanation for incorrect options

• Acetic acid $\left({\mathrm{CH}}_3\mathrm{COOH}\right)$, Carbonic acid $\left({\mathrm{H}}_2{\mathrm{CO}}_3\right)$ and Phosphoric acid $\left({\mathrm{H}}_3{\mathrm{PO}}_4\right)$ are examples of weak electrolytes.
• Hence, all other options (B), (C) and (D) are incorrect.

Therefore, the correct option is (A) Sulfuric Acid.