Assertion :- Oxidation number of `S` in `HSO_(3)^(-)` is `+4`.
Reason :- Sulphur is in different oxidation state in different compounds.

Options

A. If both Assertion & Reason are True & the Reason is a correct explanation of the Assertion.
B. If both Assertion & Reason are True but Reason is not a correct explanation of the Assertion.
C. If Assertion is True but the Reason is False.
D. If both Assertion & Reason are False.

Answer

To solve the question, we need to analyze both the assertion and the reason provided.

### Step 1: Analyze the Assertion
The assertion states that the oxidation number of sulfur in \( HSO_3^- \) is \( +4 \).

1. **Identify the oxidation states**:
- Hydrogen (H) has an oxidation state of \( +1 \).
- Oxygen (O) has an oxidation state of \( -2 \).

2. **Set up the equation**:
Let the oxidation state of sulfur (S) be \( x \).
The overall charge of the ion \( HSO_3^- \) is \( -1 \). Therefore, we can write the equation:
\[ +1 + x + 3(-2) = -1 \]

3. **Simplify the equation**:
\[ +1 + x - 6 = -1 \]
\[ x - 5 = -1 \]
\[ x = +4 \]

4. **Conclusion**:
The oxidation number of sulfur in \( HSO_3^- \) is indeed \( +4 \). Thus, the assertion is **true**.

### Step 2: Analyze the Reason
The reason states that sulfur is in different oxidation states in different compounds.

1. **Examples of sulfur oxidation states**:
- In \( H_2SO_4 \) (sulfuric acid), sulfur has an oxidation state of \( +6 \).
- In \( SO_2 \) (sulfur dioxide), sulfur has an oxidation state of \( +4 \).
- In \( H_2S \) (hydrogen sulfide), sulfur has an oxidation state of \( -2 \).

2. **Conclusion**:
It is true that sulfur can exhibit different oxidation states in various compounds. Therefore, the reason is also **true**.

### Step 3: Determine the Relationship
Now we need to determine if the reason correctly explains the assertion.

- The assertion states the specific oxidation state of sulfur in \( HSO_3^- \) is \( +4 \).
- The reason states that sulfur can have different oxidation states in different compounds, but it does not explain why the oxidation state in \( HSO_3^- \) is \( +4 \).

### Final Conclusion
Both the assertion and the reason are true, but the reason does not correctly explain the assertion. Therefore, the correct answer is:

**Option B**: Both assertion and reason are true, but the reason is not the correct explanation of the assertion.

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