Joule Expansion (Free Expansion of Ideal Gas)

This interactive simulator explores Joule Expansion in Thermodynamics. Ideal gas into vacuum: Q = W = ΔU = 0; ΔS = nR ln 2 when volume doubles. Use the controls to change the scenario; watch the visualization and any graphs or readouts to connect the model with lectures, labs, and homework.

Who it's for: Best once you already know the basic definitions and want to build intuition. Typical context: Thermodynamics.

Key terms

  • joule
  • expansion
  • joule expansion
  • thermodynamics

How it works

A microscopic cartoon of irreversible free expansion: same mean kinetic energy, larger positional disorder, and positive entropy change.