Which of the following is soluble in boiling water, but less soluble in cold water?

Options

A. `PbCl_(2)`
B. `PbCr_(2)`
C. `PbI_(2)`
D. all of these

Answer

To solve the question "Which of the following is soluble in boiling water, but less soluble in cold water?", we will analyze the solubility of the given compounds, which are lead chloride (PbCl2), lead bromide (PbBr2), and lead iodide (PbI2).

### Step-by-Step Solution:

1. **Identify the Compounds**: The compounds in question are:
- Lead Chloride (PbCl2)
- Lead Bromide (PbBr2)
- Lead Iodide (PbI2)

2. **Research Solubility Trends**: It is known that many salts exhibit different solubility in hot versus cold water. Specifically, the solubility of certain lead halides increases with temperature.

3. **Analyze Lead Halides**:
- **Lead Chloride (PbCl2)**: This compound is known to be soluble in boiling water but less soluble in cold water.
- **Lead Bromide (PbBr2)**: Similar to lead chloride, lead bromide is also soluble in boiling water but has reduced solubility in cold water.
- **Lead Iodide (PbI2)**: Lead iodide follows the same trend, being soluble in boiling water but less soluble in cold water.

4. **Conclusion**: Since all three compounds (PbCl2, PbBr2, and PbI2) are soluble in boiling water but less soluble in cold water, we can conclude that the correct answer is:
- **All of these** (option 4).

### Final Answer:
The correct choice is **All of these** (option 4).