Entropy. Suppose the heat capacity of some system has the form
Cv = aT + bT^3
for temperatures from zero up to some temperature of interest.
Calculate its entropy at temperature T. Under what conditions is your result valid?
Suppose there is a phase change at some temperature less than T, and, like the melting of water, that phase change requires some input of heat. Discuss how that would change your approach to finding the entropy.
You might use,
Cv =
S(U,V,N) = NkB{ln N(3h^2N