Sulphanilic acid is a/an:

Options

A. Arrhenius acid
B. Lewis base
C. Neither (A) or (B)
D. Both (A) and (B)

Explanation

To determine whether sulphanilic acid is an Arrhenius acid, a Lewis acid, or both, we can follow these steps:

### Step 1: Understand the Structure of Sulphanilic Acid
Sulphanilic acid has a benzene ring with an amino group (-NH2) and a sulfonic acid group (-SO3H) attached to it. The presence of these functional groups is crucial in determining its acidic and basic properties.

### Step 2: Identify the Acidic Properties
The sulfonic acid group (-SO3H) can donate a proton (H⁺) to a solution, which classifies it as an Arrhenius acid. According to the Arrhenius definition, an acid is a substance that increases the concentration of H⁺ ions in aqueous solution.

### Step 3: Identify the Basic Properties
The amino group (-NH2) has a lone pair of electrons that can accept a proton (H⁺), allowing it to act as a Lewis base. According to the Lewis definition, a base is a substance that can donate a pair of electrons.

### Step 4: Conclusion
Since sulphanilic acid can both donate a proton (acting as an Arrhenius acid) and accept a proton (acting as a Lewis base), it can be classified as both an Arrhenius acid and a Lewis base.

### Final Answer
Sulphanilic acid is both an Arrhenius acid and a Lewis base.

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