preface to fifteenth edition

2.20 SECTION 2
TABLE 2.2
Physical and Chemical Symbols and Definitions (Continued)
M. Thermodynamics (continued)
Name Symbol SI unit Definition
B
* B
Molality basis a m am,B exp RT
B
* B
Mole fraction basis a x ax,B exp RT
Activity (referenced to
B
* B
Raoult’s law)
a
aB exp
RT
Activity coefficient (referenced
to Henry’s law):
Concentration basis c a c,B c,B c B /c 0
Molality basis m a m,B m,B m B /m 0
Mole fraction basis x a x,B x,B x B
Activity coefficient (referenced
f
f B a B /x B
to Raoult’s law)
Affinity of reaction A J·mol 1 A (G/) p,T
Celsius temperature , t C /C T/K 273.15
Chemical potential J·mol 1 B (G/n B ) T,p,n
Compressibility:
Isentropic S Pa 1 S (1/V)(V/p) S
Isothermal T Pa 1 T (1/V)(V/p) T
Compressibility factor Z Z pV m /RT
Cubic expansion coefficient , V , K 1 (1/V)(V/T) p
Enthalpy H J H U pV
Entropy S J·K 1 dS dq/T
Equilibrium constant K 0 , K K exp( r G/RT)
Equilibrium constant:
Concentration basis K c (mol · m )
K c c
Molality basis K m (mol · m )
K m m
Pressure basis K p Pa K p p
Fugacity f Pa fB B lim (p B/ B)
T
p:0
Fugacity coefficient B f B /p B
Gibbs energy G J G H TS
Heat q, Q J
Heat capacity:
At constant pressure C p J·K 1 C p (H/T) p
At constant volume C V J·K 1 C V (U/T) V
Helmholtz energy A J A U TS
Internal energy U U q w
Ionic strength:
Concentration basis I c , I mol · kg 3 2
I c 1
⁄2mBzB
Molality basis I m , I mol · kg 1 Im
1 ⁄2mBz
2
B
Joule-Thomson coefficient , JT K·Pa 1 (T/p) H
Linear expansion coefficient
1 K 1 1 (l/l)(l/T)
Massieu function J J·K 1 J A/T
Molar quantity X X m (varies) X m X/n
Osmotic coefficient:
Molality basis m (* )/(RTM m )
m A A A B
Mole fraction basis x ( *)/(RT ln x )
x A A A