Which is an extensive property?

Options

A. Temperature
B. Molar heat capacity
C. Gibb’s free energy
D. Molar volume

Explanation

To determine which of the given options is an extensive property, we first need to understand the definitions of extensive and intensive properties.

### Step-by-Step Solution:

1. **Define Extensive and Intensive Properties**:
- **Extensive Properties**: These properties depend on the amount of substance present in a system. Examples include mass, volume, and total energy.
- **Intensive Properties**: These properties do not depend on the amount of substance. Examples include temperature, pressure, and density.

2. **Analyze the Options**:
- We need to evaluate each of the four options provided in the question to identify which one is extensive.

3. **Evaluate Temperature**:
- Temperature is an intensive property because it remains constant regardless of the amount of substance. If you take a substance and divide it, the temperature of both parts remains the same.

4. **Evaluate Molar Heat Capacity**:
- Molar heat capacity is defined for one mole of a substance. It does not change when the amount of substance changes, making it an intensive property.

5. **Evaluate Gibbs Free Energy**:
- Gibbs free energy is dependent on the amount of substance in the system. If you have more moles of a substance, the Gibbs free energy will change proportionally. Therefore, it is an extensive property.

6. **Evaluate Molar Volume**:
- Molar volume is defined as the volume occupied by one mole of a substance. Like molar heat capacity, it is also an intensive property because it does not change with the amount of substance.

7. **Conclusion**:
- After evaluating all the options, the only extensive property among them is Gibbs free energy. Thus, the answer is **Gibbs free energy**.

### Final Answer:
The extensive property is **Gibbs free energy**.