Estimation of the Thermodynamic Properties of Hydrocarbons at 298.15 K Cite as: Journal of Physical and Chemical Reference Data 17, 1637 (1988); https://doi.org/10.1063/1.555814 Submitted: 11 September 1986 . Published Online: 15 October 2009 Eugene S. Domalski, and Elizabeth D. Hearing ARTICLES YOU MAY BE INTERESTED IN Estimation of the Thermodynamic Properties of C-H-N-O-S-Halogen Compounds at 298.15 K Journal of Physical and Chemical Reference Data 22, 805 (1993); https:// doi.org/10.1063/1.555927 Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III Journal of Physical and Chemical Reference Data 25, 1 (1996); https://doi.org/10.1063/1.555985 Additivity Rules for the Estimation of Molecular Properties. Thermodynamic Properties The Journal of Chemical Physics 29, 546 (1958); https://doi.org/10.1063/1.1744539 Journal of Physical and Chemical Reference Data 17, 1637 (1988); https://doi.org/10.1063/1.555814 17, 1637 © 1988 American Institute of Physics for the National Institute of Standards and Technology. Estimation of the Thermodynamic Properties of Hydrocarbons at 298.15 K Eugene S. Domalski and Elizabeth D. Hearing 1 Chemical Thermodynamics Division, Center for Chemical Physics, National Institute of Standards and Technology, Gaithersburg, Maryland 20899 ReceIved September 11, 1986; revised manuscript received February 2, 1988 An estimation method developed by S.W. Benson and coworkers, for calculating the thermodynamic properties of organic compounds in the gas phase, has been extended to the liquid and solid phases for hydrocarbon compounds at 298.15 K. The second order approach which includes nearest neighbor interactions has been applied to the condensed phase. A total of 1311 comparisons are made between experimentally determined values and those calculated using additive group values. Of the 559 comparisons given for the enthalpy of formation (ArHO) in the gas, liquid, and solid phases, the average difference (residual), without regard to sign, is 2.6 kJ/mol. The average differences for 390 comparisons for the heat capacity (Cp 0) and 352 comparisons for the entropy (SO) in the three phases are 1.9 and 2.3 J/mol·K, respectively. The good agreement between experimental and calculated values shows that the Benson group additivity approach to the estimation of ther­ modynamic properties of organic compounds is applicable to the liquid and solid phases as well as the gas phase. Appendices provide example calculations of the thermodynamic properties of selected hydrocarbon compounds, total symmetry numbers, and methyl repulsion corrections. Most of the 144 references listed offer an indication of the activity in the development of estimation methods for calculat­ ing thermodynamic properties since 1931. Key words: condensed phase; enthalpy of formation; entropy; estImation methods; gas phase; heat capacity; hydrocarbons; thermodynamic properties. Contents 1. Introduction ............................ 1638 Appendix C. Methyl Repulsion Corrections for 2. Discussion of Results .................... 1639 Branched Hydrocarbons . 1651 2.1. n -Alkanes .......................... 1639 Appendix D. Example Calculations of Total 2.2. Substituted Alkanes ................. 1640 Symmetry Number for Some Hydrocarbon 2.3. Linear Alkenes ..................... 1641 Compounds ............................ 1655 2.4. Substituted Alkenes ................. 1641 2.5. Alkynes ............................ 1641 List of Tables 2.6. Aromatic Hydrocarbons. '" ......... 1641 2.7. Cycloalkanes and Related Hydro- Table I. Additive group contribution values carbons ............................ 1642 for hydrocarbons at 298.15 k ...... 1658 3. Symmetry Numbers and Entropy ......... 1642 Table 2. Ring strain corrections to be applied 4. Summary and Conclusions ............... 1642 to cycloalkanes and rclated hydrocar- 5. Acknowledgments .............. 1643 bons ............................ 1660 6. References ............................. 1643 Table 3. n-Alkane hydrocarbons in the gas phase at 298.15 K ................ 1661 Appendix A. Example Calculations of Enthalpy of Table 4. n -Alkane hydrocarbons in the liquid Formation, Heat capacity, and Entropy at phase at 298.15 K ................ 1661 298.15 K for Some Hydrocarbon Compounds .... 1648 Table 5. n-Alkane hydrocarbons in the solid Appendix B. Comparison of Calculated Thermody­ phase at 298.15 K ................ 1662 namic Properties in the Gas Phase with Benson's Table 6. Substituted alkane hydrocarbons (ter- Valuesat298.15K .............. 1650 tiary carbon) in the gas phase at 298.15 K ........................ 1662 Table 7. Substituted alkane hydrocarbons (ter­ Ipresent address: 2247 Regina Drive, Clarksburg, MD 20871. tiary carbon) in the liquid phase at 298.15 K......................... 1663 ©1988 by the U. S. Secretary of Commerce on behalf of the United Table 8. Substituted alkane hydrocarbons (ter­ States. This copyright IS assigned to the American Institute of Physics and the American Chemical Society. tiary carbon) in the solid phase at Reprints available from ACS; see Reprints List at back of issue. 298.15 K ..... ,. .. ... 1664 0047-2689/88/041637-42/$07.00 1637 J. Phys. Chern. Ref. Data, Vol. 17, No.4, 1988 1638 E. S. DOMALSKI AND E. D. HEARING Table 9. Substituted alkane hydrocarbons (qua­ to be generally acceptable to scientists within and be­ ternary carbon) in the gas phase at tween the disciplines of physical chemistry and chemical 298.15 K. 1664 engineering. The attractive features of the Benson ap­ Table 10. Substituted alkane hydrocarbons (qua­ proach consist of simple additivity, 'clarity of notation, ternary carbon) in the liquid phase at second order character, i.e., inclusion of nearest-neigh­ 298.15 K................................ 1664 bor interactions, ease of application, and satisfactory Table 11. Substituted alkane hydrocarbons (qua­ agreement between the estimated thermodynamic prop­ ternary carbon) in the solid phase at erty and its experimentally determined value. Initially, 298.15 K. 1665 focus was directed toward estimation of thermodynamic Table 12. Linear alkene hydrocarbons in the gas properties of organic compounds in the gas phase. The phase at 298.15 K . 1665 development of numerical methods oriented toward esti­ Table 13. Linear alkene hydrocarbons in the liq- mation of thermodynamic properties in the condensed uid phase at 298.15 K.............. 1666 phase has also been reported (69SHA, 71SHA, 77LUR/ Table 14. Linear alkene hydrocarbons in the BEN), but primary attention has usually been placed solid phase at 298.15 K ... 1667 upon gas phase processes. The estimation procedure de­ Table 15. Substituted alkene hydrocarbons in veloped by Henson and coworkers has been adopted into the gas phase at 298.15 K . 1668 CHETAH, the ASTM Chemical Thermodynamic and Table 16. Substituted alkene hydrocarbons in Energy Release Evaluation Program (74SEA/FRE), for the liquid phase at 298.15 K . 1669 the estimation of thermodynamic properties of organic Table 17. Substituted alkene hydrocarbons in compounds in the gas phase and for the classification of the solid phase at 298.15 K . 1669 chemical compounds or compositions according to Table 18. Alkyne hydrocarbons in the gas phase whether they are likely to be impact sensitive. at 298.15 K. 1670 The purpose of this paper is to extend the Benson Table 19. Alkyne hydrocarbons in the liquid group contribution values to the liquid and solid phases phase at 298.15 K . 1670 for hydrocarbon compounds, and when possible, to Table 20. Alkyne hydrocarbons in the solid provide improved group contribution values for the gas phase at 298.15 K . 1670 phase. The thermodynamic properties at 298.15 K con­ Table 21. Aromatic hydrocarbons in the gas sidered are: enthalpy of formation, heat capacity, and phase at 298.15 K . 1670 entropy. The approach taken in the evaluation of data Table 22. Aromatic hydrocarbons in the liquid and in the development of group values consisted of cal­ phase at 298.15 K . 1672 culating and examining group increments in a systematic Table 23. Aromatic hydrocarbons in the solid manner. This procedure was followed by the selection of phase at 298.15 K . 1674 group values which appeared to give minimum residuals Table 24. Cycloalkane and related hydrocar- between the calculated and experimental values. The de­ bons in the gas phase at 298.15 K ... 1675 velopment of groups and group values followed the path Table 25. Cycloalkane and related hydrocar- from alkanes to alkenes, alkynes, aromatic hydrocarbons, bons in the liquid phase at 298.15 K. 1676 cycloalkanes, and other hydrocarbon derivatives. A Table 26. Cycloalkane and related hydrocar- global least squares, least sums, or regression-type fit of bons in the solid phase at 298.15 K . 1678 all the group values was not carried out because of dif­ ferences in the quality of the data and because of the 1. Introduction minimal amount of data available for certain group val­ ues. Computations were performed using a conventional For many years, thermodynamicists have been active desk-top electronic calculator. It is expected that the re­ in the development of numerical methods which corre­ sults we obtained are approximately equivalent to what late molecular structure and sub-structure with a corre­ would have been derived from a weighted regression sponding energy contribution to a thermodynamic analysis. property. Some indication of this activity can be found A companion document, 89DOM/HEA, is in prepara­ by examining the 144 references