Question

Identify the intensive property from the following:
(A) volume
(B) mass
(C) enthalpy
(D) temperature

Answer 1

Hint: We need to find the intensive property. Intensive properties do not depend upon the size or quantity of matter whereas extensive properties depend upon the quantity of matter present in the system.

Complete step by step solution:
Let us understand about intensive and extensive properties in detail. If we have a thermodynamic system, then the intensive property will not depend upon the mass of the system. Intensive properties do not depend upon the size or quantity of matter. Hence melting and boiling points are intensive properties. If you take 10 gram of a substance or 100 gram of the substance, its melting point will be the same; it will not depend upon the mass of the substance taken. These properties cannot be computed, they need to be experimentally measured. Examples are conductivity, pressure, density, refractive index, viscosity, surface tension, pH, molarity etc.
The extensive property of a system depends upon the quantity of matter in the system. For an extensive property, its total value will be equal to the sum of the values for the parts of the system. We can compute the value of an extensive property. All the colligative properties are extensive properties since they depend upon the quantity of the non-volatile solute added to the solution. Some of the examples of extensive properties include volume, internal energy, length, mass, enthalpy, entropy, Gibbs free energy etc.
We can convert an extensive property into an intensive property by specifying the unit amount of the substance. Hence mass and volume are extensive properties but density (mass per unit volume) and specific volume (volume per unit mass) are intensive properties of the substance. Similarly heat capacity for a substance is an extensive property but specific heat capacity is an intensive property of the substance. Generally, the ratio of two extensive properties is always intensive.
Now let us solve the question. We need to find intensive property. Volume, mass and enthalpy are extensive properties whereas temperature is an intensive property.

Hence the correct answer is (D) temperature.

Note: Always remember that any molar property is an intensive property because it is an extensive property per unit mole of the substance and thus becomes independent of the amount of the substance. Hence molar volume, molar heat capacity etc. are intensive properties.