A cylinder fitted with a frictionless piston contains 2mol of a monatomic ideal gas at 300K. The gas expands, doing 1500J of work, and its temperature falls to 250K. (Take the molar heat capacity at constant volume for a monatomic gas as CV=23R.)
a. (a) Find the change in internal energy ΔU of the gas.
b. (b) Determine the heat Q exchanged between the gas and the surroundings during the expansion.
c. (c) From the sign and magnitude of Q, classify the process as adiabatic or non-adiabatic. State your reasoning clearly.