13.38. Equations analogous to Eqs. (10.15) and (10.16) apply for excess properties. Because ln i is a partial property with respect to GE/RT, these analogous equations can be written for ln1 and ln2 in a binary system. (a) Write these equations, and apply them to Eq. (13.42) to show that Eqs. (13.43) and (13.44) are indeed obtained. (b) The alternative procedure is to apply Eq. (13.7). Show that by doing so Eqs. (13.43) and (13.44) are again reproduced