The metal ion(s) which is/are not precipitated when `H_(2)S`is passed with `HCl` is

Options

A. `Zn^(2+)`
B. `Ni^(2+)`
C. `Cd^(2+)`
D. `Mn^(2+)`

Answer

To solve the question regarding which metal ions are not precipitated when H₂S is passed with HCl, we can follow these steps:

### Step 1: Understand the Reaction Conditions
When H₂S (hydrogen sulfide) is passed in an acidic medium (like HCl), it is used to precipitate certain metal ions based on their solubility products. The acidic environment affects the precipitation of different metal ions.

**Hint:** Remember that the acidity of the solution can influence the solubility of metal sulfides.

### Step 2: Identify the Groups of Metal Ions
Metal ions can be classified into different groups based on their precipitation behavior with H₂S:
- **Group 2 Basic Radicals:** These include ions like Cd²⁺, Pb²⁺, Hg²⁺, which precipitate as sulfides in the presence of H₂S and HCl.
- **Group 4 Basic Radicals:** These include ions such as Zn²⁺, Ni²⁺, and Mn²⁺, which do not precipitate with H₂S in the presence of HCl.

**Hint:** Familiarize yourself with the classification of metal ions based on their behavior with H₂S.

### Step 3: Analyze Each Metal Ion
Now, let's analyze the given metal ions:
1. **Zn²⁺ (Zinc):** This ion does not precipitate with H₂S in HCl. It requires NH₄OH for precipitation.
2. **Ni²⁺ (Nickel):** Similar to zinc, nickel does not precipitate with H₂S in HCl and requires NH₄OH for precipitation.
3. **Cd²⁺ (Cadmium):** This ion is a Group 2 radical and will precipitate as CdS when H₂S is passed in HCl.
4. **Mn²⁺ (Manganese):** Manganese also does not precipitate with H₂S in HCl and requires NH₄OH for precipitation.

**Hint:** Check the solubility rules for metal sulfides to determine which ions precipitate.

### Step 4: Conclusion
Based on the analysis, the metal ions that are **not precipitated** when H₂S is passed with HCl are:
- Zn²⁺
- Ni²⁺
- Mn²⁺

Thus, the correct answer includes Zn²⁺, Ni²⁺, and Mn²⁺.

**Final Answer:** The metal ions which are not precipitated when H₂S is passed with HCl are Zn²⁺, Ni²⁺, and Mn²⁺.