At`25^(@)C`the highest osmotic pressure is exhibited by `0.1M` solution of

Options

A. `CaCl_(2)`
B. KCl
C. glucose
D. urea

Explanation

To determine which 0.1 M solution exhibits the highest osmotic pressure at 25°C, we can use the formula for osmotic pressure:

\[ \pi = i \cdot C \cdot R \cdot T \]

Where:
- \(\pi\) = osmotic pressure
- \(i\) = van 't Hoff factor (number of particles the solute dissociates into)
- \(C\) = molarity of the solution
- \(R\) = universal gas constant (0.0821 L·atm/(K·mol))
- \(T\) = temperature in Kelvin (25°C = 298 K)

### Step-by-Step Solution:

1. **Identify the van 't Hoff factor (i)** for each solute:
- For **CaCl₂**:
- It dissociates into 1 Ca²⁺ ion and 2 Cl⁻ ions.
- Therefore, \(i = 1 + 2 = 3\).

- For **KCl**:
- It dissociates into 1 K⁺ ion and 1 Cl⁻ ion.
- Therefore, \(i = 1 + 1 = 2\).

- For **Glucose**:
- It does not dissociate in solution.
- Therefore, \(i = 1\).

- For **Urea**:
- It also does not dissociate in solution.
- Therefore, \(i = 1\).

2. **Calculate the effective concentration (i * C)** for each solution:
- For **CaCl₂**:
- \(i \cdot C = 3 \cdot 0.1 = 0.3\)

- For **KCl**:
- \(i \cdot C = 2 \cdot 0.1 = 0.2\)

- For **Glucose**:
- \(i \cdot C = 1 \cdot 0.1 = 0.1\)

- For **Urea**:
- \(i \cdot C = 1 \cdot 0.1 = 0.1\)

3. **Compare the effective concentrations**:
- CaCl₂: 0.3
- KCl: 0.2
- Glucose: 0.1
- Urea: 0.1

4. **Determine the highest osmotic pressure**:
- The highest value of \(i \cdot C\) is for CaCl₂, which is 0.3.

### Conclusion:
The 0.1 M solution that exhibits the highest osmotic pressure at 25°C is **CaCl₂**.