Identify the extensive quantities from the following :

Options

A. Gibb's energy
B. Entropy
C. Refractive index
D. Specific heat

Explanation

To identify the extensive quantities from the given options, we need to understand the definition of extensive and intensive properties.

### Step-by-Step Solution:

1. **Define Extensive Properties**: Extensive properties are those that depend on the amount of substance present. Examples include mass, volume, and total energy.

2. **Define Intensive Properties**: Intensive properties do not depend on the amount of substance. Examples include temperature, pressure, and refractive index.

3. **Analyze Each Property**:
- **Gibbs Energy**: It is derived from enthalpy and entropy, both of which depend on the mass of the substance. Therefore, Gibbs energy is an extensive property.
- **Entropy**: Similar to Gibbs energy, entropy is also dependent on the mass of the substance. Thus, it is an extensive property.
- **Refractive Index**: The refractive index remains constant regardless of the amount of substance. Hence, it is an intensive property.
- **Specific Heat**: Specific heat is defined as the heat required to raise the temperature of a unit mass by one degree. It does not depend on the total mass of the substance, making it an intensive property.

4. **Conclusion**: From the analysis, the extensive properties identified are:
- Gibbs Energy
- Entropy

### Final Answer:
The extensive quantities from the given options are:
- Gibbs Energy
- Entropy

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