In this Demonstration, the user identifies isothermal, reversible-adiabatic, and irreversible-adiabatic processes of an ideal gas in a step-by-step procedure. Upon starting and whenever “new problem” is selected, the Demonstration selects either an expansion or a compression process, and either a pressure-temperature or pressure-volume diagram. Select your answer from the possible options (a, b, c, d, e) and then select “show solution” to see the correct answer. The “hint” button provides a hint for each step, and once “show solution” is selected, the user cannot go back.