Which of the following anions are producing same gas on treatment with `(Zn+ " dil." H_(2)SO_(4))`.
`I :SO_(3)^(2-) " " II : HSO_(3)^(-) " " III : S^(2-) " " IV : Cl^(-)`

Options

A. I and II only
B. I, II and III only
C. I, II, III and IV
D. I, III and IV only

Answer

To determine which anions produce the same gas when treated with zinc and dilute sulfuric acid (H₂SO₄), we will analyze each anion given in the question.

### Step-by-Step Solution:

1. **Identify the Anions**:
- We have four anions to consider:
- I: SO₃²⁻ (sulfite ion)
- II: HSO₃⁻ (bisulfite ion)
- III: S²⁻ (sulfide ion)
- IV: Cl⁻ (chloride ion)

2. **Reactions with Zinc and Dilute H₂SO₄**:
- When zinc (Zn) reacts with dilute H₂SO₄, it generally reduces the anions and can produce gases such as hydrogen sulfide (H₂S) or sulfur dioxide (SO₂).

3. **Analyze Each Anion**:
- **For SO₃²⁻ (sulfite ion)**:
- The reaction with Zn and dilute H₂SO₄ produces sulfur dioxide (SO₂) gas.
- Reaction:
\[ \text{SO}_3^{2-} + 2H^+ \rightarrow \text{SO}_2 + H_2O \]

- **For HSO₃⁻ (bisulfite ion)**:
- The reaction with Zn and dilute H₂SO₄ also produces sulfur dioxide (SO₂) gas.
- Reaction:
\[ \text{HSO}_3^{-} + H^+ \rightarrow \text{SO}_2 + H_2O \]

- **For S²⁻ (sulfide ion)**:
- The reaction with Zn and dilute H₂SO₄ produces hydrogen sulfide (H₂S) gas.
- Reaction:
\[ \text{S}^{2-} + 2H^+ \rightarrow \text{H}_2\text{S} \]

- **For Cl⁻ (chloride ion)**:
- The reaction with Zn and dilute H₂SO₄ does not produce any gas; instead, it may produce zinc chloride (ZnCl₂) in solution.
- Reaction:
\[ \text{Cl}^- + Zn^{2+} \rightarrow \text{ZnCl}_2 \]

4. **Conclusion**:
- The anions that produce the same gas (SO₂) when treated with zinc and dilute H₂SO₄ are:
- I: SO₃²⁻
- II: HSO₃⁻
- Therefore, the answer is **I and II only**.

### Final Answer:
The anions producing the same gas on treatment with (Zn + dil. H₂SO₄) are **I and II only**.