What happens to the entropy of a system when the volume is increased?

When the volume of a system is increased, the entropy of the system typically increases. Entropy is a measure of the number of ways in which the energy of a system can be arranged or distributed among its particles. When the volume is expanded, the particles within the system have more space to occupy, which increases the number of accessible microstates.

This concept is rooted in the statistical interpretation of thermodynamics, where an increase in volume allows for a greater range of microstates (configurations of particles), thereby increasing the disorder within the system. The relationship between volume and entropy also aligns with the second law of thermodynamics, which states that the total entropy of an isolated system can never decrease over time.

In practical terms, when a gas is allowed to expand, for instance, it can spread out into the available space, allowing for higher configurational possibilities. As entropy is linked to the degree of freedom available to the particles in a system, increasing the volume directly contributes to an increase in entropy, capturing the idea that a more spacious system can exhibit greater disorder.