Which of the following ppt is insoluble in `NH_(3)` solution ?

Options

A. `AgI`
B. `Ag_(2)S`
C. `AgCl`
D. `AgBr`

Answer

To determine which of the given precipitates is insoluble in ammonia (NH₃) solution, we will analyze each option step by step.

### Step 1: Analyze AgI (Silver Iodide)
- When AgI is treated with NH₃, it forms a complex:
\[ \text{AgI} + 2\text{NH}_3 \rightarrow \text{[Ag(NH}_3\text{)}_2]^+ + \text{I}^- \]
- The complex formed is insoluble in ammonia.
- **Conclusion**: AgI is insoluble in NH₃.

### Step 2: Analyze Ag₂S (Silver Sulfide)
- When Ag₂S is treated with NH₃, it forms:
\[ \text{Ag}_2\text{S} + 4\text{NH}_3 \rightarrow 2\text{[Ag(NH}_3\text{)}^+] + \text{S}^{2-} \]
- The complex formed is also insoluble in ammonia.
- **Conclusion**: Ag₂S is insoluble in NH₃.

### Step 3: Analyze AgCl (Silver Chloride)
- When AgCl is treated with NH₃, it forms:
\[ \text{AgCl} + 2\text{NH}_3 \rightarrow \text{[Ag(NH}_3\text{)}_2]^+ + \text{Cl}^- \]
- The complex formed is soluble in ammonia.
- **Conclusion**: AgCl is soluble in NH₃.

### Step 4: Analyze AgBr (Silver Bromide)
- When AgBr is treated with NH₃, it forms:
\[ \text{AgBr} + 2\text{NH}_3 \rightarrow \text{[Ag(NH}_3\text{)}_2]^+ + \text{Br}^- \]
- The complex formed is also soluble in ammonia.
- **Conclusion**: AgBr is soluble in NH₃.

### Final Answer:
The precipitates that are insoluble in NH₃ are:
- **AgI (Silver Iodide)**
- **Ag₂S (Silver Sulfide)**

### Summary of Correct Options:
- **Correct Options**: AgI and Ag₂S
- **Incorrect Options**: AgCl and AgBr

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