Consider 0.1 mol of an ideal gas contained in a cylinder of volume 2.5 dm3 at a pressure of 1 bar and a temperature of 301 K. Next, suppose you consider three different processes for changing the state of the gas sample to one in which the volume is reduced to 0.25 dm3, the pressure is increased to 10 bar, and the temperature is 301 K (the same as the temperature in the initial state). The paths of the three alternative processes are specified as follow:Process #1 is a two-step process in which the gas sample is first heated at constant volume until the pressure reaches a value of 10 bar, and then the gas is cooled under constant pressure (10 bar) until its equilibrium volume is reduced to 0.25 dm3 and its temperature is 301 K. Process #2 is a two-step process in which the gas sample is first cooled under constant pressure (1 bar) until its equilibrium volume is reduced to 0.25 dm3, and then the gas is heated under constant volume conditions until its pressure reaches a value of 10 bar and its temperature is 301 K. Process #3 is a single-step process in which the gas is isothermally compressed from its initial state to its final state at a fixed temperature of 301 K. Which of the three processes above would require the least amount of work in effecting the specified change of state, and what would be the ∆U (change in internal energy) for this process?

MCQs on thermodynamics in classical mechanics systems. Topics include the first, second, and third laws of thermodynamics, energy, work, enthalpy, and entropy, spontaneity, chemical potential, equilibrium, phase changes, and chemical kinetics.