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ThermophysicalData[Chemicals]

  

Property

  

access thermodynamic data

 

Calling Sequence

Parameters

Options

Description

Examples

References

Compatibility

Calling Sequence

Property(output, species, inputopts, opts)

Parameters

output

-

symbol or string for the desired output quantity

species

-

symbol or string representing the required chemical

inputopts

-

(optional) equation of the form s=value, where s is temperature, "temperature", T or "T"

opts

-

(optional) one of more options, as described below

Options

• 

useunits : true or false show the output with units

• 

explicit : true or false show the output in polynomial form

Description

• 

The Property function returns the thermodynamic data defined in McBride et al. (2002).

• 

The data returned is at the standard state.

– 

If species is a gas, the standard state is 1 bar.

– 

If species is crystalline or liquid, the standard state is 1 atm.

• 

The output parameter is one of Hmolar, Smolar, Cpmolar, MolarMass,  HeatOfFormation or Comments. It can be given as a symbol or a string. Refer to the tables below for alternative names that are accepted by this command.

• 

If output is Hmolar, Smolar or Cpmolar, then an equation of the form temperature=value needs to be supplied.

– 

temperature can be replaced by "temperature", T or "T".

– 

value can be a name, a numeric value, or a numeric value with a unit of K .

– 

If value is a name and explicit is false (the default), then the unevaluated function is returned.

– 

If value is a name and explicit=true or explicit is specified, then an expression in value is returned. The expression is an empirical correlation for output as defined in McBride et al. (2002).

– 

If value is numeric, then it is assumed to be the temperature in Kelvin.

– 

If value is numeric with a unit of K or if useunit=true or useunit is specified, then the result returned by Property will have a unit. No other temperature unit apart from K can be used.

– 

This table describes the results returned by the Property command.

Output

Quantity

Unit of Returned Value

Hmolar, HMOLAR, molar_specific_enthalpy, molarspecificenthalpy

Molar enthalpy

J/mol

Smolar, SMOLAR, molar_specific_entropy, molarspecificentropy

Molar entropy

J/mol/K

Cpmolar, CPMOLAR, molar_specific_constant_pressure_specific_heat, molarspecificconstantpressurespecificheat

Molar heat capacity at constant pressure

J/mol/K

• 

If output is MolarMass or HeatOfFormation, then the following is true.

– 

If the option useunit has the value true, the result returned by the Property command will have a unit.

– 

This table describes the data returned by the Property command.

Output

Quantity

Unit of Returned Value

MolarMass, M, MOLARMASS, MOLAR_MASS, MOLEMASS, molar_mass, molemass

Molar mass

g/mol

HeatOfFormation

Heat of formation at 298.15

J/mol

• 

If output is Comments then additional information (as defined in McBride et al., 2002) about the chemical is returned.

Examples

withThermophysicalData:-Chemicals

GetSpecies,Property

(1)

Determine the enthalpy of CO2 with and without units

PropertyHmolar,CO2,temperature=300

−393441.2212

(2)

PropertyHmolar,CO2,temperature=300UnitK

393441.2212Jmol

(3)

Determine the molecular weight of CO2 with and without units

PropertyMolarMass,CO2

44.0095000

(4)

PropertyMolarMass,CO2,useunits

44.0095000gmol

(5)

Return an empirical correlation for the molar enthalpy of CO2

PropertyHmolar,CO2,temperature=T,explicit

8.314510T49436.50540T2626.4116010lnTT+5.301725240+0.001251906908T7.09102909310−8T21.92249719510−10T3+5.69935560210−14T445281.98460T200.000<T1000.000117696.2419T21788.791477lnTT+8.2915231900.00004611578390T+1.62122562710−9T24.72763328010−13T3+1.26600731810−16T439083.50590T1000.000<T6000.0001.544423287109T2+1.016847056106lnTT256.1405230+0.01684700540T7.27061445710−7T2+1.74785521010−11T31.76847030010−16T48.043214510106T6000.000<T20000.000

(6)

Given an enthalpy, backsolve for the temperature

fsolvePropertyHmolar&comma;CO2&comma;temperature=T=393811.1213UnitJmol&comma;T=280UnitK

289.9999991K

(7)

Calculate the Gibbs Energy of Formation of ammonia at 298.15 K, given the reaction N2g&plus;3H2g2NH3g

withUnitsSimple&colon;

Temperature

T298.15UnitK

T298.15K

(8)

Enthalpy

h_N2PropertyHmolar&comma;N2&comma;temperature=T&semi;h_H2PropertyHmolar&comma;H2&comma;temperature=T&semi;h_NH3PropertyHmolar&comma;NH3&comma;temperature=T

h_N29.91588462610−6Jmol

h_H24.95794231310−6Jmol

h_NH345940.00004Jmol

(9)

Entropy

s_N2PropertySmolar&comma;N2&comma;temperature=T&semi;s_H2PropertySmolar&comma;H2&comma;temperature=T&semi;s_NH3PropertySmolar&comma;NH3&comma;temperature=T

s_N2191.6097115JmolK

s_H2130.6810143JmolK

s_NH3192.7702891JmolK

(10)

Change in enthalpy and entropy per mole of NH3

DeltaH0.52h_NH3h_N23h_H2&semi;DeltaS0.52s_NH3s_N23s_H2

DeltaH45940.00004Jmol

DeltaS99.05608810JmolK

(11)

Hence the Gibbs Energy of Formation

DeltaGDeltaHDeltaST

DeltaG16406.42737m2kgmols2

(12)

convertDeltaG&comma;units&comma;kJmol

16.40642737kJmol

(13)

References

  

McBride, Bonnie J.; Zehe, Michael J.; and Gordon, Sanford. NASA Glenn Coefficients for Calculating Thermodynamic Properties of Individual Species; 2002; https://www.grc.nasa.gov/WWW/CEAWeb/TP-2002-21556.htm.

Compatibility

• 

The ThermophysicalData:-Chemicals:-Property command was introduced in Maple 2018.

• 

For more information on Maple 2018 changes, see Updates in Maple 2018.

See Also

ThermophysicalData

ThermophysicalData/Chemicals/ChemicalNames

ThermophysicalData/Chemicals/GetSpecies