Which of the following anions are identified by dil. HCl :

Options

A. `NO_(2)^(-),NO_(3)^(-),CO_(3)^(2-)`
B. `NO_(2)^(-),NO_(3)^(-),SO_(3)^(2-)`
C. `S^(2-),SO_(3)^(2-),NO_(2)^(-)`
D. `CH_(3)CO O^(-),I^(-),CO_(3)^(2-)`

Answer

To determine which anions are identified by dilute hydrochloric acid (HCl), we need to analyze each option provided in the question.

### Step-by-Step Solution:

1. **Understanding the Reaction with Dilute HCl**:
- Dilute HCl can react with certain anions to produce identifiable products. Common anions that react with dilute HCl include carbonate (CO3^2-), sulfite (SO3^2-), and nitrite (NO2^-).

2. **Analyzing Each Option**:
- **Option A: NO2^-, NO3^-, CO3^2-**
- NO2^- (Nitrite) reacts with dilute HCl to produce nitrogen dioxide (NO2), which can be identified by its brown color.
- NO3^- (Nitrate) does not react with dilute HCl in a way that produces a noticeable change.
- CO3^2- (Carbonate) reacts with dilute HCl to produce carbon dioxide (CO2), which can be identified by the evolution of gas.
- **Conclusion**: This option is partially correct (NO2^- and CO3^2-).

- **Option B: NO2^-, NO3^-, SO3^2-**
- NO2^- is correct as discussed.
- NO3^- does not react with dilute HCl.
- SO3^2- (Sulfite) reacts with dilute HCl to produce sulfur dioxide (SO2), which can be identified by its pungent smell and the evolution of gas.
- **Conclusion**: This option is partially correct (NO2^- and SO3^2-).

- **Option C: CO2^-, SO3^2-, NO2^-**
- CO2^- is not a valid anion; it seems to be a typographical error (possibly meant to be CO3^2-).
- SO3^2- is correct as discussed.
- NO2^- is correct as discussed.
- **Conclusion**: This option is partially correct (assuming CO2^- is a typo for CO3^2-).

- **Option D: CS3^-, COO^-, I^-, CO3^2-**
- CS3^- (Thioformate) is not typically identified with dilute HCl.
- COO^- (Carboxylate) does not react in a way that produces a noticeable change with dilute HCl.
- I^- (Iodide) does not react with dilute HCl to produce a noticeable change.
- CO3^2- is correct as discussed.
- **Conclusion**: This option is incorrect.

3. **Final Conclusion**:
- After analyzing all options, the correct anions that can be identified by dilute HCl are NO2^- and CO3^2- from Option A, and SO3^2- from Option B. However, the most comprehensive option that includes the correct anions is Option B.

### Final Answer:
The correct option is **B: NO2^-, NO3^-, SO3^2-** (considering NO3^- does not contribute but the other two do).