Calculate the work for each of the following processes beginning with a gas sample in a piston assembly with T = 305 K, P = 1.79 atm, and V = 4.29 L:

(a) Irreversible expansion against a constant external pressure of 1.00 atm to a final volume of 6.52 L;

(b) Isothermal, reversible expansion to a final volume of 6.52 L.