Which of the following is not an oxyacid ?

Options

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

Explanation

To determine which of the following is not an oxyacid, we first need to understand what an oxyacid is. An oxyacid is an acid that contains oxygen in its molecular structure.

Let's analyze the given options one by one:

1. **Hydrochloric Acid (HCl)**:
- The formula for hydrochloric acid is HCl.
- It dissociates into H⁺ and Cl⁻ ions.
- There are no oxygen atoms present in its structure.
- Therefore, hydrochloric acid is **not an oxyacid**.

2. **Sulfuric Acid (H₂SO₄)**:
- The formula for sulfuric acid is H₂SO₄.
- It dissociates to give 2 H⁺ ions and SO₄²⁻ ions.
- Sulfuric acid contains oxygen atoms in its structure.
- Thus, sulfuric acid is an **oxyacid**.

3. **Nitric Acid (HNO₃)**:
- The formula for nitric acid is HNO₃.
- It dissociates to give H⁺ ions and NO₃⁻ ions.
- Nitric acid also contains oxygen atoms in its structure.
- Therefore, nitric acid is an **oxyacid**.

4. **Acetic Acid (CH₃COOH)**:
- The formula for acetic acid is CH₃COOH.
- It partially dissociates to give H⁺ ions and CH₃COO⁻ ions.
- Acetic acid contains oxygen atoms in its structure.
- Hence, acetic acid is also an **oxyacid**.

After analyzing all the options, we can conclude that the only compound that does not contain oxygen and is therefore not an oxyacid is **hydrochloric acid (HCl)**.

### Final Answer:
The correct answer is **hydrochloric acid (HCl)**.

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