APPENDIXC SYMBOLS FORPHYSICALQUANTITIES 474

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Symbol Physical quantity SI unit

wel electrical work J

w^0 nonexpansion work J

x mole fraction in a phase (dimensionless)

Cartesian space coordinate m

y mole fraction in gas phase (dimensionless)

Cartesian space coordinate m

Z compression factor (compressibility factor) (dimensionless)

z mole fraction in multiphase system (dimensionless)

charge number of an ion (dimensionless)

electron number of cell reaction (dimensionless)

Cartesian space coordinate m

Greek letters

alpha

degree of reaction, dissociation, etc. (dimensionless)

cubic expansion coefficient K^1

gamma

surface tension N m^1 , J m^2

(^) i activity coefficient of speciesi,
pure liquid or solid standard state (dimensionless)
(^) m;i activity coefficient of speciesi,
molality basis (dimensionless)
(^) c;i activity coefficient of speciesi,
concentration basis (dimensionless)
(^) x;i activity coefficient of speciesi,
mole fraction basis (dimensionless)
(^)  mean ionic activity coefficient (dimensionless)
pressure factor (activity of a reference state) (dimensionless)
epsilon
 efficiency of a heat engine (dimensionless)
energy equivalent of a calorimeter J K^1
theta

angle of rotation (dimensionless)

kappa
 reciprocal radius of ionic atmosphere m^1
T isothermal compressibility Pa^1
mu
 chemical potential J mol^1
JT Joule–Thomson coefficient K Pa^1
nu
 number of ions per formula unit (dimensionless)