Hydrogen sulphide is not a group reagent for (basic radical)

Options

A. `2^(nd)` group radicals
B. `3^(rd)` group radicals
C. `4^(th)` group radicals
D. `5^(th)` group radicals

Answer

To determine which group hydrogen sulfide (H₂S) is not a group reagent for, we will analyze the basic radicals and their corresponding group reagents.

### Step-by-Step Solution:

1. **Understanding Group Reagents**: In qualitative analysis, group reagents are used to precipitate certain ions from a solution. Each group of basic radicals has a specific group reagent.

2. **Identifying Groups**: The basic radicals are classified into different groups based on their solubility and the reagents used to precipitate them. The groups are typically numbered from 1 to 5.

3. **Group 2 and Group 4**: Hydrogen sulfide (H₂S) is confirmed to be a group reagent for both Group 2 and Group 4. This means that H₂S can precipitate the ions present in these groups.

4. **Group 3**: For Group 3, the group reagent is ammonium sulfide (NH₄)₂S, which is prepared by reacting H₂S with ammonium chloride (NH₄Cl). Although H₂S is involved in the preparation of ammonium sulfide, it is not directly used as the group reagent for Group 3.

5. **Group 5**: For Group 5, the group reagent is ammonium carbonate (NH₄)₂CO₃. Therefore, H₂S is not a group reagent for Group 5.

6. **Conclusion**: Based on the analysis, hydrogen sulfide (H₂S) is not a group reagent for Group 5.

### Final Answer:
Hydrogen sulfide is not a group reagent for Group 5.

---