One mole of an ideal gas at 0 celcius is subjected to changes below, calculate the change in entropy of the gas:
i) Gas is expanded reversibly and isothermally to twice its initial volume. DONE - 5.76 J/K
ii)A similar expansion to i. is performed reversibly and adiabatically [hint, for an ideeal gas undergoing reversible adiabatic expansion TV^(gamma - 1) = constant]
I know delta Q = -nRT Ln (Vf/Vi) for a reversible isothermal expansion
delta S = delta Q / absolute T
dE = dW + dQ
The Attempt at a Solution
for a isolated system i know the entropy change would be zero, but as it doesnt state this i dont feel that i can just state "assuming system is isolated entropy change is zero"
so im stuck how to go about this..