Which of the following is a not a strong acid ?

Options

A. Hydrochloric acid
B. Sulphuric acid
C. Nitric acid
D. Acetic acid

Explanation

To determine which of the following is not a strong acid, we need to analyze each option based on their ability to dissociate and donate hydrogen ions (H⁺) in solution.

### Step-by-Step Solution:

1. **Understanding Strong and Weak Acids**:
- Strong acids are substances that completely dissociate in water, releasing a high concentration of H⁺ ions.
- Weak acids only partially dissociate in solution, resulting in a lower concentration of H⁺ ions.

2. **Analyzing the Options**:
- **Hydrochloric Acid (HCl)**:
- HCl is a strong acid because it completely dissociates in water to form H⁺ and Cl⁻ ions.
- **Sulfuric Acid (H₂SO₄)**:
- H₂SO₄ is also a strong acid. It dissociates completely in water, releasing H⁺ ions and HSO₄⁻ ions.
- **Nitric Acid (HNO₃)**:
- HNO₃ is another strong acid that fully dissociates in solution to produce H⁺ and NO₃⁻ ions.
- **Acetic Acid (CH₃COOH)**:
- Acetic acid is a weak acid. It does not completely dissociate in solution; instead, it exists mostly in its molecular form (CH₃COOH) with only a small amount dissociating into H⁺ and CH₃COO⁻ ions.

3. **Conclusion**:
- Among the given options, acetic acid (CH₃COOH) is the only one that is not a strong acid. Therefore, the correct answer is **Acetic Acid (CH₃COOH)**.

### Final Answer:
**Acetic Acid (CH₃COOH)** is not a strong acid.

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