(

)

(4

*

∫

d*T *=

4*T*s4

(

)

*B*(3) 4*B*(4) *T *3 *T *3

Cp

+

3*T*s3

(

)

*B*(2) 3*B*(3) + 6*B*(4) *T *2 *T *2

Cp

+

2*T*s2

*B*(1) 2*B*(2) + 3*B*(3) 4*B*(4) *T * *T*

Cp

+

Ts

* T*

+ 2*C*Cp arctan f 1

*T*s

* T*

2*C*Cp arctan rw 1

* T*s

[

]

+ *B*C ) *B*C ) + *B*C ) *B*C ) + *B*C ) ln(Tf ) ln(Trw ) .

(0

(1

(2

(3

(4

(43)

p

lated similarly. Initially, we can define the apparent molal constant pressure heat

capacity of the solute, φCp,NaCl(aq) (J K1 mol1), in a NaCl aqueous solution as

[C

]

O

φ

=

(44)

where *C*p,m = constant-pressure molar heat capacity of the solution

(J K1 mol1)

O

standard state (i.e., pure) (J K1 mol1)

The change in entropy for the solute in its reference state is calculated from

O

O

∆*S*NaCl(aq)

=∫

d*T *.

(45)

The apparent molal constant-pressure heat capacity was estimated with the Pitzer

model:

O

1 + b *I*m

ν *z*Na zCl AC

φ

=

+

ln

1 + b *I*r

2b

[

]

(

)

2νNa νCl RT 2 (m *m*r )BNaCl + *m*2 *m*r νNa zNaCNaCl

2

(46)

17