Which of the following is a mono basic acid?

Options

A. `H_2 SO_4`
B. `CH_3 COOH`
C. `H_3 PO_3`
D. `H_2 CO_3`

Explanation

To determine which of the following is a monobasic acid, we need to understand the definition of a monobasic acid. A monobasic acid is one that can donate only one hydrogen ion (H⁺) per molecule when dissolved in water.

Let's analyze the options provided:

1. **H₂SO₄ (Sulfuric Acid)**:
- When H₂SO₄ dissociates, it releases 2 H⁺ ions:
\[ H₂SO₄ \rightarrow 2H⁺ + SO₄^{2-} \]
- Since it releases 2 H⁺ ions, it is classified as a dibasic acid.

2. **CH₃COOH (Acetic Acid)**:
- When CH₃COOH dissociates, it releases 1 H⁺ ion:
\[ CH₃COOH \rightarrow CH₃COO^{-} + H⁺ \]
- Since it releases only 1 H⁺ ion, it is classified as a monobasic acid.

3. **H₃PO₃ (Phosphorous Acid)**:
- When H₃PO₃ dissociates, it releases 3 H⁺ ions:
\[ H₃PO₃ \rightarrow 3H⁺ + PO₃^{3-} \]
- Since it releases 3 H⁺ ions, it is classified as a tribasic acid.

4. **H₂CO₃ (Carbonic Acid)**:
- When H₂CO₃ dissociates, it releases 2 H⁺ ions:
\[ H₂CO₃ \rightarrow 2H⁺ + CO₃^{2-} \]
- Since it releases 2 H⁺ ions, it is classified as a dibasic acid.

After analyzing all the options, we can conclude that the only acid that donates one H⁺ ion is **CH₃COOH (Acetic Acid)**.

**Final Answer**: The correct answer is **option 2: Acetic Acid (CH₃COOH)**.