Problem S2.3. Two containers, each of volume V, contain ideal gas held at temperature T and pressure P. The gas in chamber 1 consists of Na molecules of type a and N,b molecules of type

b. The gas in chamber 2 consists of N2,a molelcules of type a and N2,b molecules of type

b. Assume that Na + N1,b = N2a + N2b. The gases are allowed to mix so the final temperature is T and the final pressure is P (cf. Fig. 2.21).

(a) Compute the entropy of mixing.

(b) What is the entropy of mixing if Na = N2,a and N = N2,b-

(c) What is the entropy of mixing if N = N2,b and Nb = N2,a = 0. Discuss your results for

(b) and (c).