The reagent that distinguishes between silver and lead salt is

Options

A. `H_(2)S` gas
B. dil. HCI solution after this dissolved in hot water
C. `NH_(4)CI("solid") + NH_(4)OH("solution")`
D. `NH_(4)CI("solid") + NH_(4))_(2)CO_(3)` solution

Explanation

To determine the reagent that distinguishes between silver and lead salts, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Salts**:
- Silver salt is typically silver chloride (AgCl).
- Lead salt is often lead(II) chloride (PbCl2).

2. **Analyzing Solubility**:
- Silver chloride (AgCl) is insoluble in both cold and hot water.
- Lead(II) chloride (PbCl2) is insoluble in cold water but soluble in hot water.

3. **Choosing the Reagent**:
- The reagent we are considering is dilute hydrochloric acid (HCl).
- When dilute HCl is added to a solution containing these salts, it does not dissolve AgCl, but it will dissolve PbCl2 when the solution is heated.

4. **Performing the Test**:
- Add dilute HCl to the mixture of salts.
- Heat the solution.
- Observe the solubility:
- If the salt remains undissolved, it is AgCl.
- If it dissolves, it is PbCl2.

5. **Conclusion**:
- Therefore, dilute HCl is the reagent that can distinguish between silver and lead salts based on their solubility characteristics.

### Final Answer:
The reagent that distinguishes between silver and lead salt is **dilute hydrochloric acid (HCl)**.

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