A 2.50 mol sample of an ideal gas for which C_{V ,m} = 3/2R undergoes the following two-step process: 

a. From an initial state of the gas described by T = 13.1????C and P = 1.75 × 10⁵ Pa, the gas undergoes an isothermal expansion against a constant external pressure of 3.75 × 10⁴ Pa until the volume has doubled. 

b. Subsequently, the gas is cooled at constant volume. The temperature falls to −23.6°C. Calculate q, w, ΔU, and ΔH for each step and for the overall process.