1) Calculate the change in the entropies of the system, the surrounding, and the total change in entropy, when the volume of a sample of argon gas of mass 2.9 g at 298 K increases from 1.2 dm3 to 4.6 dm3 in an isothermal reversible expansion. Assume this gas is an ideal gas and the atomic weight of argon is 39.948 g/mol.

2) In a Carnot engine the cold reservoir is at 0 . If 10 kJ of heat is withdrawn from the hot reservoir and 3 kJ of work is generated, at which temperature is the hot source?