`H_(2)S` gas on passing through an alkline solution , forms a white precipitate .The solution contains ions of

Options

A. Pb
B. Zn
C. Cu
D. Ni

Explanation

To solve the question, we need to analyze the reaction of hydrogen sulfide (H₂S) gas when it is passed through an alkaline solution and the formation of a white precipitate.

### Step-by-Step Solution:

1. **Understanding the Reaction**:
When H₂S gas is introduced into an alkaline solution, it can react with certain metal ions present in the solution to form metal sulfides.

2. **Identifying the Precipitate**:
The question states that a white precipitate is formed. Different metal ions react with H₂S to form different colored precipitates:
- Zinc (Zn²⁺) forms zinc sulfide (ZnS), which is a white precipitate.
- Nickel (Ni²⁺), Copper (Cu²⁺), and Lead (Pb²⁺) form nickel sulfide (NiS), copper sulfide (CuS), and lead sulfide (PbS), respectively, which are all black precipitates.

3. **Conclusion**:
Since the precipitate formed is white, we can conclude that the alkaline solution must contain zinc ions (Zn²⁺) because it is the only one among the common metal ions that forms a white precipitate with H₂S.

### Final Answer:
The solution contains ions of **Zinc (Zn²⁺)**.

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