Out of internal energy (I), boiling point (II), pH (III) and E.M.F. of the cell (IV) intensive properties are :

Options

A. I, II
B. II, III, IV
C. I, III, IV
D. All of these

Explanation

To determine which of the given properties are intensive, we need to understand the definitions of intensive and extensive properties.

**Step 1: Define Intensive and Extensive Properties**
- Intensive properties are those that do not depend on the amount of substance present. Examples include boiling point, density, and pH.
- Extensive properties depend on the amount of substance present. Examples include mass, volume, and internal energy.

**Step 2: Analyze Each Property**
1. **Internal Energy (I)**:
- Internal energy is the total energy contained within a system, which includes kinetic and potential energy. It depends on the amount of substance present.
- **Conclusion**: Internal energy is an extensive property.

2. **Boiling Point (II)**:
- The boiling point of a substance is the temperature at which it changes from liquid to gas. It remains constant regardless of the amount of substance (e.g., 100°C for water).
- **Conclusion**: Boiling point is an intensive property.

3. **pH (III)**:
- pH is a measure of the acidity or basicity of a solution. It remains the same regardless of the volume of the solution (e.g., the pH of a 0.1 M HCl solution is the same whether you take 10 mL or 20 mL).
- **Conclusion**: pH is an intensive property.

4. **E.M.F. of the Cell (IV)**:
- The electromotive force (E.M.F.) of a cell is the voltage generated by the cell. It does not depend on the amount of reactants present in the cell.
- **Conclusion**: E.M.F. is an intensive property.

**Step 3: Summarize the Findings**
- From the analysis:
- Internal Energy (I) - Extensive Property
- Boiling Point (II) - Intensive Property
- pH (III) - Intensive Property
- E.M.F. of the Cell (IV) - Intensive Property

**Final Answer**: The intensive properties among the given options are Boiling Point (II), pH (III), and E.M.F. of the Cell (IV).