Heptane
- Formula: C7H16
- Molecular weight: 100.2019
- IUPAC Standard InChI: InChI=1S/C7H16/c1-3-5-7-6-4-2/h3-7H2,1-2H3
- IUPAC Standard InChIKey: IMNFDUFMRHMDMM-UHFFFAOYSA-N
- CAS Registry Number: 142-82-5
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
The 3d structure may be viewed using Java or Javascript. - Isotopologues:
- Other names: n-Heptane; Dipropylmethane; Heptyl hydride; Skellysolve C; n-C7H16; Eptani; Heptan; Heptanen; Gettysolve-C; NSC 62784
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Gas phase thermochemistry data
Go To: Top, References, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DRB - Donald R. Burgess, Jr.
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | -187.8 ± 0.79 | kJ/mol | Ccb | Prosen and Rossini, 1945 | ALS |
| ΔfH°gas | -189.3 | kJ/mol | N/A | Davies and Gilbert, 1941 | Value computed using ΔfHliquid° value of -225.9±1.3 kj/mol from Davies and Gilbert, 1941 and ΔvapH° value of 36.6 kj/mol from Prosen and Rossini, 1945.; DRB |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 127.65 | 200. | Scott D.W., 1974 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculation [ Pitzer K.S., 1944, Pitzer K.S., 1946].; GT |
| 154.64 | 273.15 | ||
| 165.2 ± 0.3 | 298.15 | ||
| 165.98 | 300. | ||
| 210.66 | 400. | ||
| 252.09 | 500. | ||
| 287.44 | 600. | ||
| 317.15 | 700. | ||
| 342.25 | 800. | ||
| 363.59 | 900. | ||
| 381.58 | 1000. | ||
| 397.06 | 1100. | ||
| 410.45 | 1200. | ||
| 422.58 | 1300. | ||
| 435.14 | 1400. | ||
| 443.50 | 1500. |
Constant pressure heat capacity of gas
| Cp,gas (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 191.50 ± 0.19 | 357.10 | Waddington G., 1947 | GT |
| 198.78 ± 0.20 | 373.15 | ||
| 210.75 ± 0.21 | 400.40 | ||
| 225.31 ± 0.23 | 434.35 | ||
| 238.49 ± 0.24 | 466.10 |
References
Go To: Top, Gas phase thermochemistry data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D.,
Heats of combustion and formation of the paraffin hydrocarbons at 25° C,
J. Res. NBS, 1945, 263-267. [all data]
Davies and Gilbert, 1941
Davies, G.F.; Gilbert, E.C.,
Heats of combustion and formation of the nine isomeric heptanes in the liquid state,
J. Am. Chem. Soc., 1941, 63, 2730-2732. [all data]
Scott D.W., 1974
Scott D.W.,
Chemical Thermodynamic Properties of Hydrocarbons and Related Substances. Properties of the Alkane Hydrocarbons, C1 through C10 in the Ideal Gas State from 0 to 1500 K. U.S. Bureau of Mines, Bulletin 666, 1974. [all data]
Scott D.W., 1974, 2
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Pitzer K.S., 1944
Pitzer K.S.,
Thermodynamics of gaseous paraffins. Specific heat and related properties,
Ind. Eng. Chem., 1944, 36, 829-831. [all data]
Pitzer K.S., 1946
Pitzer K.S.,
The entropies and related properties of branched paraffin hydrocarbons,
Chem. Rev., 1946, 39, 435-447. [all data]
Waddington G., 1947
Waddington G.,
An improved flow calorimeter. Experimental vapor heat capacities and heats of vaporization of n-heptane and 2,2,3-trimethylbutane,
J. Am. Chem. Soc., 1947, 69, 22-30. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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