Which statements is/are correct about sodium nitroprusside test ?

Options

A. This test is used for detection of `SO^(2-)` anion .
B. `H_(2)S` also gives positive test.
C. Formation of `Na_(2)[Fe(H_(2)O)_(5)NOS]` complex the presence of `S^(2-)` anion.
D. Iron has `+2` oxidation state in sodiumthionitroprusside complex.

Answer

To determine which statements are correct about the sodium nitroprusside test, we will analyze each option step by step.

### Step-by-Step Solution:

1. **Understanding the Sodium Nitroprusside Test**:
- The sodium nitroprusside test is primarily used to detect the presence of sulfide ions (SO₃²⁻) and certain other anions.

2. **Evaluating Each Statement**:
- **Option A**: "This test is used for the reduction of SO₃²⁻ anion."
- This statement is **correct**. The sodium nitroprusside test is indeed used for the detection of sulfide ions.

- **Option B**: "H₂S also gives a positive test."
- This statement is **incorrect**. Hydrogen sulfide (H₂S) does not give a positive result in the sodium nitroprusside test.

- **Option C**: "Formation of [Fe(H₂O)₅(NO)₂]²⁻ complex determines the presence of H₂S ion."
- This statement is **incorrect**. The complex mentioned does not form in the presence of H₂S, and thus does not indicate its presence.

- **Option D**: "The ion has a +2 oxidation state in sodium thionitroprusside complex."
- This statement is **correct**. In the sodium thionitroprusside complex, the iron ion is indeed in the +2 oxidation state.

3. **Conclusion**:
- The correct options are A and D.

### Final Answer:
The correct statements about the sodium nitroprusside test are:
- A: This test is used for the reduction of SO₃²⁻ anion.
- D: The ion has a +2 oxidation state in sodium thionitroprusside complex.