1 mole of `AgI//Ag^(+)` sol is coagulated by

Options

A. `100 ml 1 M K_(2)SO_(4)`
B. `Fe^(+3)`
C. 1 mol of `Na^(+)`
D. None of these

Answer

To solve the problem of coagulating 1 mole of `AgI//Ag^(+)` sol, we need to understand the principles of colloidal stability and coagulation.

### Step-by-Step Solution:

1. **Understand the Nature of Colloidal Sols**:
- Colloidal particles are stabilized by electric charges. In this case, `AgI` sol is positively charged due to the presence of `Ag^+` ions.

**Hint**: Remember that the stability of colloidal solutions is due to the electric charges on the particles.

2. **Identify the Coagulation Process**:
- Coagulation occurs when the charges on the colloidal particles are neutralized, allowing them to come together and precipitate out of the solution.

**Hint**: Coagulation is the process of neutralizing the charges on colloidal particles.

3. **Determine the Required Ions for Coagulation**:
- To coagulate a positively charged sol, we need to introduce negatively charged ions. This will neutralize the positive charge and promote aggregation.

**Hint**: Look for negatively charged ions in the options provided.

4. **Analyze the Given Options**:
- **Option 1**: 100 ml of 1 M K2SO4 - This contains `SO4^(2-)`, which is a negatively charged ion.
- **Option 2**: Fe3+ - This is a positively charged ion and will not coagulate the sol.
- **Option 3**: Na+ - This is also a positively charged ion and will not coagulate the sol.
- **Option 4**: None of these - This option is not applicable since we have a suitable option.

**Hint**: Evaluate each option based on whether it contains negatively charged ions.

5. **Select the Correct Option**:
- The only option that provides negatively charged ions is K2SO4, which will effectively coagulate the `AgI` sol.

**Hint**: Choose the option that contains the necessary negatively charged ions for coagulation.

### Final Answer:
The correct option to coagulate 1 mole of `AgI//Ag^(+)` sol is **100 ml of 1 M K2SO4**.