An aqueous solution contains `Hg^(2+),Hg_(2)^(2+),Pb^(2+),Ag^(+),Bi_(3+)` and `Cd^(2+)`.Out of these, how many ions will produce white precipitate with dilule `HCl` ?

Explanation

To determine how many ions from the given list will produce a white precipitate with dilute HCl, we need to analyze each ion's behavior when reacted with HCl.

### Step-by-Step Solution:

1. **Identify the Ions Present**: The ions present in the solution are:
- Hg²⁺ (Mercury(II))
- Hg₂²⁺ (Mercury(I))
- Pb²⁺ (Lead(II))
- Ag⁺ (Silver)
- Bi³⁺ (Bismuth)
- Cd²⁺ (Cadmium)

2. **Consider the Reaction with Dilute HCl**: When these ions react with dilute HCl, they may form precipitates. We need to check which of these ions form white precipitates.

3. **Analyze Each Ion**:
- **Hg²⁺**: Does not form a precipitate with dilute HCl.
- **Hg₂²⁺**: Reacts with HCl to form Hg₂Cl₂ (Mercury(I) chloride), which is a white precipitate.
- **Pb²⁺**: Reacts with HCl to form PbCl₂ (Lead(II) chloride), which is a white precipitate.
- **Ag⁺**: Reacts with HCl to form AgCl (Silver chloride), which is also a white precipitate.
- **Bi³⁺**: Does not form a precipitate with dilute HCl.
- **Cd²⁺**: Does not form a precipitate with dilute HCl.

4. **Count the Ions that Produce White Precipitates**: From the analysis:
- Hg₂²⁺ produces a white precipitate (Hg₂Cl₂).
- Pb²⁺ produces a white precipitate (PbCl₂).
- Ag⁺ also produces a white precipitate (AgCl).

5. **Conclusion**: The ions that produce white precipitates with dilute HCl are:
- Hg₂²⁺
- Pb²⁺
- Ag⁺

Thus, there are **three ions** that will produce a white precipitate with dilute HCl.

### Final Answer:
**3 ions** (Hg₂²⁺, Pb²⁺, Ag⁺) will produce white precipitate with dilute HCl.