Calculate the change in the entropies of the system and the surroundings, and the total change in entropy, when a sample of nitrogen gas of 14 g at 298 k and 1.0 bar doubles its volume in (a) an isothermal reversible expansion, (b) an adiabatic reversible expansion. 3.13(b) calculate the change in the entropies of the system and the surroundings, and the total change in entropy, when the volume of a sample of argon gas of mass 21 g at 298 k and 1.50 bar increases from 1.20 dm to 4.60 dm in (a) an isothermal reversible expansion, (b) an isothermal irreversible expansion against pp 0, and (c) an adiabatic reversible expansion.