Expand 1.00 mol of a monatomic gas, initially at 7.00 kPa and 469 K, from initial volume Vi = 0.557 m³ to final volume Vf = 2.70 m³. At any instant during the expansion, the pressure p and volume V of the gas are related by p = 7.00 exp[(Vi - V)/a], with p in kilopascals, Vi and V are in cubic meters, and a = 1.30 m³. What are the final (a) pressure and (b) temperature of the gas? (c) How much work is done by the gas during the expansion? (d) What is the change in entropy of the gas for the expansion? (Hint: Use two simple reversible processes to find the entropy change.)