Sodium hydrogen carbonate when added to acetic acid evolves a gas. Which of the following statements are true about the gas evolved?
(i) It turns lime milky
(ii) It extinguishes a burning splinter
(iii) It dissolves in a solution of sodium hydroxide
(iv) It has a pungent odour.

Options

A. (i) and (ii)
B. (i), (ii) and (iii)
C. (ii), (iii) and (iv)
D. (i) and (iv)

Explanation

To determine which statements are true about the gas evolved when sodium hydrogen carbonate (baking soda) reacts with acetic acid (vinegar), we can analyze the reaction and the properties of the gas produced.

### Step-by-Step Solution:

1. **Identify the Reaction**:
When sodium hydrogen carbonate (NaHCO₃) reacts with acetic acid (CH₃COOH), the reaction can be represented as:
\[ \text{NaHCO}_3 + \text{CH}_3\text{COOH} \rightarrow \text{CH}_3\text{COONa} + \text{CO}_2 + \text{H}_2\text{O} \]
This reaction produces sodium acetate, carbon dioxide (CO₂), and water.

2. **Analyze the Gas Evolved**:
The gas evolved in this reaction is carbon dioxide (CO₂). We will evaluate each statement based on the properties of CO₂.

3. **Statement (i)**: "It turns lime milky."
- **True**: When carbon dioxide is bubbled through lime water (a solution of calcium hydroxide), it reacts to form calcium carbonate, which is insoluble and appears as a white precipitate, turning the lime water milky.

4. **Statement (ii)**: "It extinguishes a burning splinter."
- **True**: Carbon dioxide is a non-supporter of combustion. If a burning splinter is placed in a container filled with carbon dioxide, it will be extinguished because CO₂ does not support combustion.

5. **Statement (iii)**: "It dissolves in a solution of sodium hydroxide."
- **True**: Carbon dioxide can react with sodium hydroxide to form sodium carbonate or sodium bicarbonate, depending on the concentration. Thus, it can dissolve in sodium hydroxide solution.

6. **Statement (iv)**: "It has a pungent odour."
- **False**: Carbon dioxide is a colorless and odorless gas. It does not have a pungent odor.

### Conclusion:
Based on the analysis:
- Statements (i), (ii), and (iii) are **True**.
- Statement (iv) is **False**.

### Final Answer:
- True Statements: (i), (ii), (iii)
- False Statement: (iv)