Vessels l and 2 contain v = 1.2 moles of gaseous helium.
The ratio of the vessels' volumes V21V1 = a = 2.0, and the ratio of
the absolute temperatures of helium in them T1/T2 = 6 = 1.5.
Assuming the gas to be ideal, find the difference of gas entropies in
these vessels, S2 - S1.