Question

Which among the following is NOT an extensive property?

• A. Mass
• B. Volume
• C. Pressure
• D. Internal energy

Hint:

A simple trick: If you split a system in half, extensive properties (like volume and mass) are halved, while intensive properties (like pressure, temperature, and concentration) remain exactly the same!

Answer 1

The Correct Option is C

Step 1: Understanding the Question:
We must identify which thermodynamic property in the list is an intensive property (meaning it is NOT an extensive property).

Step 2: Key Formula or Approach:
Extensive properties are physical properties that depend on the amount or size of the matter present in the system (e.g., mass, volume, total energy).
Intensive properties are physical properties that do not depend on the amount of matter in the system (e.g., temperature, pressure, density).

Step 3: Detailed Explanation:
(A) Mass is a direct measurement of the amount of matter. It is an extensive property.
(B) Volume changes proportionally as you add more matter to the system. It is an extensive property.
(C) Pressure is the force exerted per unit area. It does not depend on the total quantity of matter. For example, if you conceptually divide a container of gas in half, the pressure of the gas in each half remains exactly the same as the whole. It is an intensive property.
(D) Internal energy is the total energy of the system, which scales with the number of particles. It is an extensive property.

Step 4: Final Answer:
Pressure is NOT an extensive property, which matches option (C).