Which compound acts as oxidising agent only?

Options

A. `SO_(2)`
B. `H_(2)S`
C. `H_(2)SO_(4)`
D. `HNO_(2)`

Answer

To determine which compound acts as an oxidizing agent only, we need to analyze the oxidation states of the elements in various compounds. An oxidizing agent is a substance that gains electrons (is reduced) and, in the process, causes another substance to be oxidized.

### Step-by-Step Solution:

1. **Identify the Compounds**: We need to consider various compounds and their oxidation states. For this example, let’s analyze sulfur dioxide (SO₂) and sulfuric acid (H₂SO₄).

2. **Calculate Oxidation State of Sulfur in SO₂**:
- In SO₂, oxygen has an oxidation state of -2.
- The total oxidation state for two oxygen atoms = 2 × (-2) = -4.
- Let the oxidation state of sulfur be x. The overall charge of the molecule is 0.
- Therefore, the equation is:
\[ x + (-4) = 0 \implies x = +4 \]
- Thus, the oxidation state of sulfur in SO₂ is +4.

3. **Calculate Oxidation State of Sulfur in H₂SO₄**:
- In H₂SO₄, hydrogen has an oxidation state of +1 and oxygen is -2.
- The total oxidation state for four oxygen atoms = 4 × (-2) = -8.
- Let the oxidation state of sulfur be y. The overall charge of the molecule is 0.
- Therefore, the equation is:
\[ 2(+1) + y + 4(-2) = 0 \implies 2 + y - 8 = 0 \implies y = +6 \]
- Thus, the oxidation state of sulfur in H₂SO₄ is +6.

4. **Identify the Oxidizing Agent**:
- An oxidizing agent is typically a species with a higher oxidation state that can accept electrons.
- In this case, sulfur in H₂SO₄ has a higher oxidation state (+6) compared to sulfur in SO₂ (+4).
- Therefore, H₂SO₄ acts as an oxidizing agent.

5. **Conclusion**:
- Among the compounds analyzed, H₂SO₄ is the one that acts as an oxidizing agent only due to the higher oxidation state of sulfur.