Which of the following reagent can be used to separate `AgCl` and AgI?

Options

A. dil. `HNO_(3)`
B. `NH_(4)OH` solution
C. KCN solution
D. `Na_(2)S_(2)O_(3)` solution

Explanation

To solve the problem of separating AgCl (silver chloride) and AgI (silver iodide), we need to analyze the solubility of these compounds in the given reagents. Here’s a step-by-step breakdown of the solution:

### Step 1: Understand the Compounds
- We have two compounds: AgCl and AgI.
- Both are silver salts but have different solubility properties.

### Step 2: Analyze the Reagents
1. **Dilute HNO3 (Nitric Acid)**
- Both AgCl and AgI are insoluble in dilute HNO3.
- Therefore, this reagent cannot be used to separate them.

2. **NH4OH (Ammonium Hydroxide)**
- AgCl is soluble in NH4OH, forming a complex: [Ag(NH3)2]+.
- AgI, however, remains insoluble in NH4OH.
- This means we can separate AgCl from AgI using this reagent.

3. **KCN (Potassium Cyanide)**
- KCN acts as a complexing agent and can dissolve both AgCl and AgI.
- Thus, it cannot be used to separate them.

4. **Na2S2O3 (Sodium Thiosulfate)**
- Na2S2O3 also dissolves both AgCl and AgI, forming soluble complexes.
- Therefore, it cannot be used for separation either.

### Step 3: Conclusion
- The only reagent that can effectively separate AgCl and AgI is **NH4OH**. AgCl will dissolve, while AgI will not.

### Final Answer
The reagent that can be used to separate AgCl and AgI is **NH4OH (Ammonium Hydroxide)**.

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