Question

Which of the following are intensive properties?
(A) Heat capacity
(B) Refractive Index
(C) Specific volume
(D) Entropy

Answer 1

Hint: Intensive property is a physical property which can be measured. This property is related to the size of the material or substance.


Complete step by step solution:
-Physical property is a property which can be measured and it also describes the state of the system. The change in the physical properties leads to the change in the system. Physical properties are further classified as intensive and extensive properties.
-Intensive Property: An intensive property is independent on the amount of the substance. It is a bulk property. For example as boiling point of water is ${\text{10}}{{\text{0}}^{\text{o}}}{\text{C}}$, it will be the same for 100mL and for 1 litre. So boiling point is independent of the amount of the substance. Temperature (T), pressure (P) and density (${\text{\rho }}$) are some more examples of intensive properties.
-Extensive property: An extensive property of the system is dependent on the amount of the substance. It is not a bulk property. For example mass of a substance will vary with the amount of the substance. Some other examples are Volume, energy, length, weight.
-The ratio of two extensive properties gives an intensive property. For example density is the ratio of two extensive properties that is the ratio of mass and volume. But density is an intensive property that is independent of the amount of substance.
-Heat capacity: Heat capacity is a physical property which is the amount of heat supplied to given mass of the substance to increase the temperature by ${{\text{1}}^{\text{o}}}{\text{C}}$. As it is dependent on the amount of the substance thus heat capacity is an extensive property.
-Refractive Index: Refractive Index describes how fast light travels through a material. It is a dimensionless quantity. As it is not dependent on the amount of the substance, refractive index is an extensive property.
-Specific volume: specific volume is the ratio of volume to its mass. This means that specific volume is indirectly proportional to mass. Thus specific volume is an extensive property.
-Entropy: entropy is the thermal energy that is unavailable to do work. It is measured with respect to temperature. It is dependent on the amount of substance. Thus entropy is an extensive property.


Hence option (B) is the correct one.

Note: An extensive property can be converted to intensive property by dividing it by mass. Heat capacity is an extensive property but specific heat capacity which is the ratio of heat capacity to the mass is an intensive property.