Is hardness an intensive property or an extensive property? Is work/heat an intensive or extensive properties?
The Correct Answer and Explanation is:
Correct Answer:
- Hardness is an intensive property.
- Work and heat are extensive properties.
Explanation (300 words):
Physical properties of matter can be classified as either intensive or extensive. This classification depends on whether or not the property changes with the amount of substance present.
Hardness refers to the ability of a material to resist deformation, particularly scratching or indentation. It does not depend on the size or quantity of the material. A small diamond and a large diamond will both exhibit the same hardness, as long as the material is uniform. This makes hardness an intensive property, because it remains constant regardless of the sample size.
On the other hand, work and heat are energy-related concepts that depend directly on the extent or amount of the system being considered. Work is defined as the energy transferred when a force is applied over a distance, and heat is energy transferred between systems due to a temperature difference. Both quantities scale with the size of the system. For example, doubling the mass of a gas in a piston generally doubles the work done during expansion or compression, assuming identical conditions. Similarly, the heat required to raise the temperature of a substance increases with the quantity of that substance.
This means both work and heat are extensive properties, as they change when the size of the system changes. They are also considered path functions, meaning their values depend on the process taken rather than the state of the system. Unlike intensive properties, extensive properties cannot identify or characterize substances independently because their values are not intrinsic to the material but rather tied to the system size or the conditions applied.
Understanding the distinction between intensive and extensive properties is essential for proper thermodynamic analysis and chemical identification.
