A and B are two gases. ‘A’is identified with a glass rod dipped in `NH_3`, and the gas 'B' is identified with a glass rod dipped in `HCl`. 'A' and 'B' are respectively 

Options

A. `HCl, NO_(2)`
B. `HCl, NH_(3)`
C. `NH_(3), HCl`
D. `NH_(3), SO_(2)`

Answer

To solve the problem, we need to identify the gases A and B based on the reactions they undergo when a glass rod dipped in ammonia (NH₃) and a glass rod dipped in hydrochloric acid (HCl) are brought into contact with them.

### Step-by-Step Solution:

1. **Identify Gas A**:
- A glass rod is dipped in ammonia (NH₃) and then brought into contact with gas A.
- Ammonia is known to react with hydrochloric acid (HCl) to form ammonium chloride (NH₄Cl), which appears as white fumes.
- Therefore, if gas A produces white fumes when contacted with NH₃, gas A must be HCl.

2. **Identify Gas B**:
- A glass rod is dipped in hydrochloric acid (HCl) and then brought into contact with gas B.
- If gas B is ammonia (NH₃), it will react with HCl to also form ammonium chloride (NH₄Cl), resulting in the formation of white fumes.
- Thus, if gas B produces white fumes when contacted with HCl, gas B must be NH₃.

3. **Conclusion**:
- From the above observations, we conclude that gas A is HCl and gas B is NH₃.
- Therefore, the correct identification of gases A and B is: A = HCl and B = NH₃.

### Final Answer:
A is HCl and B is NH₃.

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