Question

Which of the following is not an extensive property?

• A. Pressure
• B. Volume
• C. Energy
• D. Entropy

Hint:

Extensive properties (e.g., volume, energy, entropy) scale with system size, while intensive properties (e.g., pressure, temperature) do not.

Answer 1

The Correct Option is A

Step 1: Understand extensive and intensive properties.
Extensive properties depend on the amount of substance in the system (e.g., they scale with the system size). Examples include mass, volume, energy, and entropy.
Intensive properties do not depend on the amount of substance and remain the same regardless of system size. Examples include pressure, temperature, and density.
Step 2: Classify each property.
(1) Pressure: Pressure (\( P \)) is defined as force per unit area (\( P = \frac{F}{A} \)). If the system is doubled in size (same material, same conditions), the pressure remains the same because it’s a ratio. Pressure is an intensive property.
(2) Volume: Volume (\( V \)) is the amount of space the system occupies. If the system size doubles, the volume doubles. Volume is an extensive property.
(3) Energy: Energy (\( E \)), such as internal energy or kinetic energy, depends on the amount of substance. Doubling the system doubles the energy. Energy is an extensive property.
(4) Entropy: Entropy (\( S \)) is a measure of disorder and scales with the system size. Doubling the system doubles the entropy. Entropy is an extensive property.
Step 3: Identify the non-extensive property.
Pressure is intensive (not extensive).
Volume, energy, and entropy are all extensive.
Step 4: Select the correct answer.
Pressure is not an extensive property, matching option (1).