Examples of User-Defined Units
The following tables give examples of expressions you can use to enter symbols. This enables you to show the values of thermodynamic variables in a variety of units.
Units of State Variables and Derived Variables and User-Specified Units
You can also use thermodynamic variables with normalizing suffixes in the expression when you enter a symbol. However, the tables do not have examples of these expressions.
In the expressions these are defined as follows:
iis for an auxiliary index or letter that corresponds to the componentcjis for an auxiliary index or letter that corresponds to the phaseph, andijstands for an auxiliary index or letter that corresponds to the componentcin the phaseph.
Intensive and Extensive Variables of a Defined System
| Quantity | Suggested Name and Expression | Unit |
|---|---|---|
For Intensive Variables of a Defined System |
||
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Temperature |
TempC = T-273.15 |
Celsius (C) |
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TempF = 1.8*T-459.67 |
Fahrenheit (F) |
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TempF = 1.8*TempC+32 |
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Pressure |
PB = P/1E5 |
bars (bar) |
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PKb = P/1E8 |
kilobars (kbar) |
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PAtm = P/101325 |
atmosphere (atm) |
|
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PSI = P/6894.76 |
pounds/sq. inch (psi) |
|
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PIHg = P/3342.11 |
inches of Hg |
|
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PTor = P/133.322 |
Tors (millimeters of Hg) |
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For Extensive Variables of a Defined System |
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Amount |
BKg = 1E-3*B |
kilograms (kg) |
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BTon = 1E-6*B |
tons |
|
|
Volume |
VDM = 1E-3*V |
cubic decimeters (dm3, l) |
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VCM = 1E-6*V |
cubic centimeters (cm3) |
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VMM = 1E-9*V |
cubic millimeters (mm3) |
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VCI = 1.6387064E-5*V |
cubic inches (in3) |
|
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VLi = 1E-3*V |
liters (l) |
|
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Energy |
GCal = G/4.1858 |
cal |
|
ACal = A/4.1858 |
cal |
|
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UCal = U/4.1858 |
cal |
|
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HCal = H/4.1858 |
cal |
|
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SCal = S/4.1858 |
Cal/K |
|
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Heat Capacity |
Cp2 = HM.T/4.1858 |
cal/mol/K |
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Cp3 = HW.T/4.1858 |
cal/g/K |
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Cp4 = HV.T/4.1858 |
cal/m3/K |
|
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Thermal Expansion |
A2 = VM.T*1E-6/VM |
1/K |
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A3 = VW.T*1E-6/VW |
1/K |
|
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Isothermal Compressibility |
B2 = -VM.P*1E-9/VM |
1/Pa |
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B3 = -VW.P*1E-9/VW |
1/Pa |
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Intensive and Extensive Variables of a System Component
| Quantity | Suggested Name and Expression | Unit |
|---|---|---|
For Intensive Variables of a System Component |
||
|
Chemical Potential |
MUi = MU(c)/4.1858 |
cal/mol |
|
MURi = MUR(c)/4.1858 |
cal/mol |
|
|
Special quantity for aqueous solution |
pH = -LOG10(ACR(H+1)) |
dimensionless |
|
Eh = MUR(ZE)/RNF where RNF=96485.309 |
volts (V) |
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For Extensive Variables of a System Component |
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Amount |
MFi = N(c)/N = X(c) |
dimensionless |
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MPi = N(c)/N*100 |
dimensionless |
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WFi = B(c)/B = W(c) |
dimensionless |
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WPi = B(c)/B*100 |
dimensionless |
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BKgi = 1E-3*B(c) |
kilograms (kg) |
|
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BToni = 1E-6*B(c) |
tons |
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Extensive Variables of a Phase
| Quantity | Suggested Name and Expression | Unit |
|---|---|---|
|
Amount |
MFj = NP(ph)/N |
dimensionless |
|
MPj = NP(ph)/N*100 |
dimensionless |
|
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WFj = BP(ph)/B |
dimensionless |
|
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WPj = BP(ph)/B*100 |
dimensionless |
|
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BKgj = 1E-3*BP(ph) |
kilograms (kg) |
|
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BTonj = 1E-6*BP(ph) |
tons |
|
|
Volume |
VCMj = 1E-3*V(ph) |
cubic decimeters (dm3, l) |
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VCMj = 1E-6*V(ph) |
cubic centimeters (cm3) |
|
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VMMj = 1E-9*V(ph) |
cubic millimeters (mm3) |
|
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Energy |
GCalj = G(ph)/4.1858 |
cal |
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ACalj = A(ph)/4.1858 |
cal |
|
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Isothermal Compressibility |
B2j = -VM(ph).P/VM(ph) |
1/Pa |
Extensive Variables of a Component in a Phase
| Quantity | Suggested Name and Expression | Unit |
|---|---|---|
|
Amount |
MFij = N(ph,c)/NP(ph) = X(ph,c) |
dimensionless |
|
MPij = N(ph,c)/NP(ph)*100 |
dimensionless |
|
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WFi = B(ph,c)/BP(ph) = W(ph,c) |
dimensionless |
|
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WPij = B(ph,c)/BP(ph)*100 |
dimensionless |
|
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BKgij = 1E-3*B(ph,c) |
kilograms (kg) |
|
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BTonij = 1E-6*B(ph,c) |
tons |
Intensive and Extensive Variables of a Species in a Phase
| Quantity | Suggested Name and Expression | Unit |
|---|---|---|
For Intensive Variables of a Species in a Phase |
||
|
Chemical Potential |
MUCalij = MU(sp,ph)/4.1858 |
cal/mol |
|
MUErgij = MU(sp,ph)*1E7 |
cal/mol |
|
|
Fugacity |
FAij = AC(sp,ph)*PATM |
atmosphere (atm) |
|
FBij = AC(sp,ph)*PB |
bars (bar) |
|
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FCij = AC(sp,ph)*PKB |
kilobars (kbar) |
|
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FTij = AC(sp,ph)*PTOR |
Tors (millimeters of Hg) |
|
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ln(Fugacity) |
LnFAij = LNAC(sp,ph)+LN(PATM) |
atmosphere (atm) |
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LnFBij = LNAC(sp,ph)+LN(PB) |
bars (bar) |
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LnFCij = LNAC(sp,ph)+LN(PKB) |
kilobars (kbar) |
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LnFTij = LNAC(sp,ph)+LN(PTOR) |
Tors (millimeters of Hg) |
|
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Special quantity for aqueous solution |
AIij=ACR(FE+3,AQ)*AH2O |
dimensionless |
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RCij=ACR(FE+3,AQ)*YH2O/Y(AQ,FE+3) where AH2O=55.508435 and YH2O=Y(AQ,H2O) |
dimensionless |
|
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WRCalij = WR(AQ,sp)/4.1858 (WR(AQ,sp) is only valid for aqueous species in a system in which the AQUEOUS solution phase is considered) |
cal/mol |
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For Extensive Variables of a Species in a Phase |
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Special quantity for aqueous solution |
MLij=Y(AQ,FE+3)*AH2O/YH2O |
molality (m) |
|
ISTR=1*IS1+1*IS2+1*IS3 where AH2O=55.508435, YH2O=Y(AQ,H2O) and ISn=.5*MLi*Zi**2+.5*MLj*Zj**2+.5*MLk*Zk**2 |
molality (m) |
|
Units for Variables of Specific Species in a Phase
In the GIBBS, DATA, PARROT and ED_EXP modules, there are quantities that describe various thermodynamic, physical, chemical and transport properties for a compound phase, and for a certain species or a given species combination in a specific solution phase. The following table describes the units for those variables.
These variables cannot be directly used in the POLY or POST modules.
| Variables | Description and Unit |
|---|---|
|
G(ph,sp) G(ph,sp;0) G(ph,sp1;sp2;...;0) |
Gibbs energy (J/mol) of a pure substance or end-member. |
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G(ph,sp1,sp2,...) L(ph,sp1,sp2,...) G(ph,sp1,sp2,...;0) L(ph,sp1,sp2,...;0) G(ph,sp1,sp2,...;...;0) L(ph,sp1,sp2,...;...;0) |
Zero-order interaction parameter (J/mol) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
G(ph,sp1,sp2,...;i) L(ph,sp1,sp2,...;i) G(ph,sp1,sp2,...;...;i) L(ph,sp1,sp2,...;...;i) |
The ith -order interaction parameter (J/mol) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
TC(ph,sp) TC(ph,sp;0) TC(ph,sp1;sp2;...;0) |
Curie temperature (K) of a pure substance or end-member. |
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TC(ph,sp1,sp2,...) TC(ph,sp1,sp2,...;0) TC(ph,sp1,sp2,...;...;0) |
Zero-order Curie-temperature contribution (K) to a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
TC(ph,sp1,sp2,...;i) TC(ph,sp1,sp2,...;...;i) |
The ith -order Curie-temperature contribution (K) to a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
BMAGN(ph,sp) BMAGN(ph,sp;0) BMAGN(ph,sp1;sp2;...;0) |
Bohr magneton number (dimensionless) of a pure substance or end-member. |
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BMAGN(ph,sp1,sp2,...) BMAGN (ph,sp1,sp2,...;0) BMAGN (ph,...;sp1,sp2,...;0) |
Zero-order Bohr magneton number (dimensionless) to a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
BMAGN(ph,sp1,sp2,...;i) BMAGN(ph,sp1,sp2,...;...;i) |
The ith -order Bohr magneton number (dimensionless) to a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
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V0(ph,sp) V0(ph,sp;0) V0(ph,sp1;sp2;...;0) |
Molar volume (m3) at 1 bar and reference T0 of a pure substance or end-member. |
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V0(ph,sp1,sp2,...) V0(ph,sp1,sp2,...;0) V0(ph,sp1,sp2,...;...;0) |
Zero-order composition-dependent molar volume (m3) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
V0(ph,sp1,sp2,...;i) V0(ph,sp1,sp2,...;...;i) |
The ith-order composition-dependent molar volume (m3) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VA(ph,sp) VA(ph,sp;0) VA(ph,sp1;sp2;...;0) |
Integrated thermal expansivity (m3/mol/K) of a pure substance or end-member. |
|
VA(ph,sp1,sp2,...) VA(ph,sp1,sp2,...;0) VA(ph,sp1,sp2,...;...;0) |
Zero-order composition-dependent thermal expansivity (m3/mol/K) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VA(ph,sp1,sp2,...;i) VA(ph,sp1,sp2,...;...;i) |
The ith -order composition-dependent thermal expansivity (m3/mol/K) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VC(ph,sp) |
High pressure fitting parameter (m3/mol) of a pure substance or endmember. |
|
VC(ph,sp1,sp2,...) |
Zero-order composition-dependent high pressure fitting parameter (m3/mol) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VC(ph,sp1,sp2,...i) |
The ith -order composition-dependent high pressure fitting parameter (m3/mol) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VK(ph,sp) |
Isothermal compressibility (m3/mol/Pa) of a pure substance or endmember. |
|
VK(ph,sp1,sp2,...) |
Zero-order composition-dependent isothermal compressibility (m3/mol/Pa) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
VK(ph,sp1,sp2,...i) |
The ith -order composition-dependent isothermal compressibility (m3/mol/Pa) of a specified binary, ternary or higher-order interactions on a certain sublattice site in a solution phase. |
|
WR(ph,sp) WR(ph,sp;0) |
Standard Born function (J/mol) of a specific aqueous species in the AQUEOUS solution phase (always with a single sublattice) under the reference-state temperature and pressure. |