compound X is tested and the results are shown in the following table.
`|{:("Test","Result",),("Aqueous NaOH is added and heated gently.","Gas released turns moist red litmus paper blue",),("Dilute HCl is added","Gas is evolved accompanied by brisk effervescence. It turns lime water milky and acidified " K_(2)Cr_(2)O_(7) " paper green.",):}|`
The compound X contains

Options

A. Ammonium and suphite ions
B. Ammonium and carbonate ions
C. Sodium and carbonate ions
D. Ammonium and sulphate ions

Explanation

To solve the problem regarding compound X and its tests, we will analyze the observations step by step.

### Step 1: Analyze the first test with Aqueous NaOH
- **Observation**: When aqueous NaOH is added and heated gently, a gas is released that turns moist red litmus paper blue.
- **Interpretation**: The gas released must be basic in nature since it turns red litmus paper blue. This indicates the presence of ammonia (NH₃) gas.

**Reaction**:
When ammonium ions (NH₄⁺) react with hydroxide ions (OH⁻) from NaOH, ammonia gas is produced:
\[ NH_4^+ + OH^- \rightarrow NH_3(g) + H_2O \]

### Step 2: Analyze the second test with Dilute HCl
- **Observation**: When dilute HCl is added, gas is evolved accompanied by brisk effervescence. The gas turns lime water milky and can also turn acidified potassium dichromate paper green.
- **Interpretation**: The gas that evolves must be either carbon dioxide (CO₂) or sulfur dioxide (SO₂). The fact that it turns lime water milky suggests that it could be CO₂, but the additional observation of turning potassium dichromate paper green indicates it is likely SO₂, as SO₂ acts as a reducing agent.

**Reactions**:
1. **Lime Water Test**:
\[ Ca(OH)_2 + SO_2 \rightarrow CaSO_3 \, (s) \, \text{(which turns lime water milky)} \]

2. **Potassium Dichromate Test**:
\[ K_2Cr_2O_7 + H_2SO_4 + SO_2 \rightarrow Cr_2(SO_4)_3 + K_2SO_4 + H_2O \]
(This reaction shows that SO₂ reduces Cr₂O₇²⁻ to Cr³⁺, which is green in color.)

### Conclusion
Based on the observations:
- The first test indicates the presence of ammonium ions (NH₄⁺).
- The second test indicates the presence of sulfite ions (SO₃²⁻), which produces SO₂ gas.

Thus, compound X contains **ammonium ions (NH₄⁺)** and **sulfite ions (SO₃²⁻)**.

### Final Answer
The compound X contains **ammonium ions (NH₄⁺) and sulfite ions (SO₃²⁻)**.

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