A 0.50 mol sample of an ideal gas is taken from state X to state Y by a reversible two-step process.
Step 1: The gas absorbs 120 J of energy as heat from a reservoir at 300 K.
Step 2: The gas absorbs 40 J of energy as heat from a reservoir at 400 K.
Determine the total entropy change of the gas for the entire process, giving your answer in J/K.