ABSTRACT

Measurements of the heat capacity of standard specimens of copper, benzoic acid, and heptane and their thermodynamic functions of molar heat capacity, change in entropy, and enthalpy have been carried out at a low-temperature thermal-physical installation in the temperature range (4.2 up to 320) K using the method of adiabatic calorimetry. The obtained data are in good agreement with the recommended values. The relative uncertainty limits of the calorimetric unit: +- 1.43 % at T = 5 K, +- 0.75 % at T = 10 K, +- 0.23 % at T = 40 K, and less than +- 0.11 % for the temperature range (90 up to 298.15) K have been determined according to the experimental data of measurements of the certified measure of oxygen-free electronic (OFE) grade copper heat capacity. According to the heptane heat capacity measurement, the values of its enthalpy and entropy of fusion at Tfus = 182.54 K, ?Hfus = (14047 +- 19.6) J*mol-1 and ?Sfus = (76.96 +- 0.11) J*mol-1*K-1, have been determined. These values are also in a satisfactory agreement with the reference data.

Compounds

#	Formula	Name
1	Cu	copper
2	C7H6O2	benzoic acid
3	C7H16	heptane

Datasets

The table above is generated from the ThermoML associated json file (link above). POMD and RXND refer to PureOrMixture and Reaction Datasets. The compound numbers are included in properties, variables, and phases, if specificied; the numbers refer to the table of compounds on the left.
Type	Compound-#	Property	Variable	Constraint	Phase	Method	#Points
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	293
POMD	1	Molar heat capacity at constant pressure, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	44
POMD	1	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	44
POMD	1	Molar entropy, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	44
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Crystal	Temperature, K; Crystal		Crystal Gas	Vacuum adiabatic calorimetry	159
POMD	2	Molar heat capacity at saturation pressure, J/K/mol ; Crystal	Temperature, K; Crystal		Crystal Gas	Vacuum adiabatic calorimetry	44
POMD	2	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	44
POMD	2	Molar entropy, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	44
POMD	3	Molar enthalpy of transition or fusion, kJ/mol ; Crystal			Crystal Liquid Air at 1 atmosphere	Adiabatic calorimetry	1
POMD	3	Triple point temperature, K ; Crystal			Crystal Liquid Gas	Adiabatic calorimetry	1
POMD	3	Molar heat capacity at saturation pressure, J/K/mol ; Crystal	Temperature, K; Crystal		Crystal Gas	Vacuum adiabatic calorimetry	153
POMD	3	Molar heat capacity at saturation pressure, J/K/mol ; Liquid	Temperature, K; Liquid		Liquid Gas	Vacuum adiabatic calorimetry	57
POMD	3	Molar heat capacity at saturation pressure, J/K/mol ; Crystal	Temperature, K; Crystal		Crystal Gas	Vacuum adiabatic calorimetry	37
POMD	3	Molar heat capacity at saturation pressure, J/K/mol ; Liquid	Temperature, K; Liquid		Liquid Gas	Vacuum adiabatic calorimetry	22
POMD	3	Molar enthalpy, kJ/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	37
POMD	3	Molar enthalpy, kJ/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vacuum adiabatic calorimetry	22
POMD	3	Molar entropy, J/K/mol ; Crystal	Temperature, K; Crystal	Pressure, kPa; Crystal	Crystal	Vacuum adiabatic calorimetry	37
POMD	3	Molar entropy, J/K/mol ; Liquid	Temperature, K; Liquid	Pressure, kPa; Liquid	Liquid	Vacuum adiabatic calorimetry	22

Thermodynamics Research Center / ThermoML | Journal of Chemical and Engineering Data

Measurement of Heat Capacity by Adiabatic Calorimetry and Calculation of Thermodynamic Functions of Standard Substances: Copper, Benzoic Acid, and Heptane (For Calibration of an Adiabatic Calorimeter)

Bissengaliyeva, M. R.[Mira R.], Gogol, D. B.[Daniil B.], Taymasova, S. T.[Shynar T.], Bekturganov, N. S.[Nuraly S.]

ABSTRACT