Problems and Solutions on Thermodynamics and Statistical Mechanics

136 Problems d Solutions on Thermodynamics d Statistical Mechanics

Solution:
Referring to Fig. 1.37, we regard the whole process as isobaric.
dS
Choose the entropy at TI as zero for the a-phase. Since T- = C,
dT
one has

S = C In T + const. : Sa = C, In , S, = S1 + C, In

The changes in chemical potential are

Since Ap' = Ap,, we have

= 1.60 x J/g.K

Therefore

= (C, - C.,)T:! In (g) - SIT2

= 23.7 J/g.

Sl

Fig. 1.37.