A sample containing 1.00 mol of an ideal monatomic gas is confined in a vertical cylinder fitted with a frictionless, movable piston. The external pressure remains constant at 1.00 atm. The gas is heated while the piston rises, and the volume increases from 2.00 L to 6.00 L. Over the course of the expansion, the temperature of the gas rises from 300 K to 400 K. The molar heat capacity at constant volume for the gas may be taken as 20.8 J mol⁻¹ K⁻¹ and assumed to remain constant over the temperature range examined.
(a) Calculate the work associated with the expansion. Report your answer in kJ and indicate its sign.
(b) Determine the change in internal energy, ΔU, for the gas during the process. Express your answer in kJ and include the sign.
(c) Using your answers to parts (a) and (b), calculate the quantity of heat, q, exchanged between the system and its surroundings. State the sign of q.
(d) Based on the signs of q and ΔU, classify the overall process for the gas as endothermic or exothermic and briefly justify your classification.