A gas is contained in a piston cylinder device which exchang

A gas is contained in a piston cylinder device which exchanges energy by work and heat transfer with the surroundings which are at 300 K. The gas expands in a process in which the energy of the gas remains constant, but the entropy increases by 0.3 kJ/K; and 0.04 kJ/K of entropy is generated due to irreversibilities. Determine the amount of work that is done by the gas. Note that the problem as stated previously without the entropy generation specified and the assumption that the gas undergoes an internally reversible process requires the additional assumption that the walls of the cylinder are very thin so that the resistance to conductive heat transfer through the walls is negligible. Of course, in both statements of the problem, the assumption is implicit that the inner and outer wall convective resistances are neglidgable as well.

Solution

As mentioned energy is constant and Internal energy is zero

== Q=W

Wmax =To(s1-s2)

W=300(0.3-0.04)

W= 78KJ