In a closed system, when the system expands into a larger volume of space, the entropy typically increases.
Entropy is a measure of the system's disorder or randomness. When the system expands into a larger volume, the number of available microstates (possible arrangements of particles) increases. As a result, the system has more possible configurations or ways to distribute its energy and particles.
In thermodynamics, the second law of thermodynamics states that the entropy of an isolated system tends to increase over time. This is often referred to as the "arrow of time" because it implies a preferred direction of spontaneous processes.
When a closed system expands into a larger volume, it allows more microstates and configurations, leading to increased disorder or randomness. As a consequence, the entropy of the system tends to increase. This increase in entropy is consistent with the second law of thermodynamics.
It's important to note that there can be exceptions or specific conditions where entropy might decrease during expansion, but these cases are typically associated with highly specific or contrived situations. In most cases, expansion into a larger volume leads to an increase in entropy.