Pentane, 2,2-dimethyl-

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.


Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, 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
Δfgas-49.29 ± 0.32kcal/molCcbProsen and Rossini, 1945ALS
Δfgas-50.07kcal/molN/ADavies and Gilbert, 1941Value computed using ΔfHliquid° value of -242.0±1.0 kj/mol from Davies and Gilbert, 1941 and ΔvapH° value of 32.5 kj/mol from Prosen and Rossini, 1945.; DRB
Quantity Value Units Method Reference Comment
gas93.901cal/mol*KN/AHuffman H.M., 1961GT

Constant pressure heat capacity of gas

Cp,gas (cal/mol*K) Temperature (K) Reference Comment
27.930200.Scott D.W., 1974Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, 2, Scott D.W., 1974]. This approach gives a good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT
36.790273.15
39.84 ± 0.1298.15
40.069300.
51.809400.
62.089500.
70.901600.
78.401700.
84.900800.
90.600900.
95.6001000.
100.001100.
103.901200.
107.001300.
111.001400.
114.001500.

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, 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
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Δfliquid-57.05 ± 0.32kcal/molCcbProsen and Rossini, 1945ALS
Δfliquid-57.9 ± 0.3kcal/molCcbDavies and Gilbert, 1941ALS
Quantity Value Units Method Reference Comment
Δcliquid-1147.85 ± 0.30kcal/molCcbProsen and Rossini, 1945Corresponding Δfliquid = -57.03 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δcliquid-1146.9 ± 0.3kcal/molCcbDavies and Gilbert, 1941Corresponding Δfliquid = -58.02 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity Value Units Method Reference Comment
liquid71.771cal/mol*KN/AHuffman, Gross, et al., 1961DH
liquid68.09cal/mol*KN/AHuffman, Parks, et al., 1930Extrapolation below 90 K, 64.10 J/mol*K.; DH

Constant pressure heat capacity of liquid

Cp,liquid (cal/mol*K) Temperature (K) Reference Comment
52.849298.15Huffman, Gross, et al., 1961T = 10 to 300 K.; DH
51.89294.1Huffman, Parks, et al., 1930T = 92 to 294 K. Value is unsmoothed experimental datum.; DH

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, 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:
BS - Robert L. Brown and Stephen E. Stein
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
Tboil352.3 ± 0.3KAVGN/AAverage of 48 out of 53 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus149. ± 2.KAVGN/AAverage of 20 out of 22 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple149.2 ± 0.9KAVGN/AAverage of 7 values; Individual data points
Quantity Value Units Method Reference Comment
Tc520.5 ± 0.5KN/ADaubert, 1996 
Tc520.44KN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4 K; TRC
Tc520.85KN/AEdgar and Calingaert, 1929Uncertainty assigned by TRC = 0.5 K; measured by Keys and Kleinschmidt; TRC
Quantity Value Units Method Reference Comment
Pc27.3 ± 0.5atmN/ADaubert, 1996 
Pc27.367atmN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.4000 atm; TRC
Pc28.4000atmN/AEdgar and Calingaert, 1929Uncertainty assigned by TRC = 0.5000 atm; measured by Keys and Kleinschmidt; TRC
Quantity Value Units Method Reference Comment
Vc0.416l/molN/ADaubert, 1996 
Quantity Value Units Method Reference Comment
ρc2.41 ± 0.05mol/lN/ADaubert, 1996 
ρc2.41mol/lN/AMcMicking and Kay, 1965Uncertainty assigned by TRC = 0.05 mol/l; TRC
Quantity Value Units Method Reference Comment
Δvap7.782kcal/molN/AMajer and Svoboda, 1985 
Δvap7.74 ± 0.02kcal/molCSvoboda, 1998AC
Δvap7.74 ± 0.02kcal/molCOsborne and Ginnings, 1947AC
Δvap7.70 ± 0.02kcal/molCOsborne and Ginnings, 1947AC
Δvap7.749kcal/molCOsborne and Ginnings, 1947, 2ALS

Reduced pressure boiling point

Tboil (K) Pressure (atm) Reference Comment
351.20.978Aldrich Chemical Company Inc., 1990BS

Enthalpy of vaporization

ΔvapH (kcal/mol) Temperature (K) Method Reference Comment
6.986352.4N/AMajer and Svoboda, 1985 
7.60 ± 0.02308.CSvoboda, 1998AC
7.50 ± 0.02315.CSvoboda, 1998AC
7.41 ± 0.02323.CSvoboda, 1998AC
7.29 ± 0.02330.CSvoboda, 1998AC
7.19 ± 0.02338.CSvoboda, 1998AC
7.03 ± 0.02348.CSvoboda, 1998AC
6.88 ± 0.02358.CSvoboda, 1998AC
6.72 ± 0.02368.CSvoboda, 1998AC
7.93292.AStephenson and Malanowski, 1987Based on data from 277. to 354. K.; AC
7.19368.AStephenson and Malanowski, 1987Based on data from 353. to 483. K.; AC
7.84300.N/AForziati, Norris, et al., 1949Based on data from 285. to 353. K.; AC
7.79303.MMWillingham, Taylor, et al., 1945Based on data from 288. to 353. K.; AC

Antoine Equation Parameters

log10(P) = A − (B / (T + C))
    P = vapor pressure (atm)
    T = temperature (K)

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K) A B C Reference
288.47 to 353.203.934281190.298-49.807Williamham, Taylor, et al., 1945

Enthalpy of fusion

ΔfusH (kcal/mol) Temperature (K) Reference Comment
1.392149.43Huffman, Gross, et al., 1961DH
1.40148.1Acree, 1991AC
1.401148.1Huffman, Parks, et al., 1930DH

Entropy of fusion

ΔfusS (cal/mol*K) Temperature (K) Reference Comment
9.316149.43Huffman, Gross, et al., 1961DH
9.460148.1Huffman, Parks, et al., 1930DH

In addition to the Thermodynamics Research Center (TRC) data available from this site, much more physical and chemical property data is available from the following TRC products:


References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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]

Huffman H.M., 1961
Huffman H.M., Low temperature thermodynamic properties of six isomeric heptanes, J. Phys. Chem., 1961, 65, 495-503. [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]

Huffman, Gross, et al., 1961
Huffman, H.M.; Gross, M.E.; Scott, D.W.; McCullough, I.P., Low temperature thermodynamic properties of six isomeric heptanes, J. Phys. Chem., 1961, 65, 495-503. [all data]

Huffman, Parks, et al., 1930
Huffman, H.M.; Parks, G.S.; Thomas, S.B., Thermal data on organic compounds. VIII. The heat capacities, entropies and free energies of the isomeric heptanes, J. Am. Chem. Soc., 1930, 52, 3241-3251. [all data]

Daubert, 1996
Daubert, T.E., Vapor-Liquid Critical Properties of Elements and Compounds. 5. Branched Alkanes and Cycloalkanes, J. Chem. Eng. Data, 1996, 41, 365-372. [all data]

McMicking and Kay, 1965
McMicking, J.H.; Kay, W.B., Vapor Pressures and Saturated Liquid and Vapor Densities of The Isomeric Heptanes and Isomeric Octanes, Proc., Am. Pet. Inst., Sect. 3, 1965, 45, 75-90. [all data]

Edgar and Calingaert, 1929
Edgar, G.; Calingaert, G., Preparation and Properties of the Isomeric Heptanes II. Physical Prop. properties, J. Am. Chem. Soc., 1929, 51, 1540. [all data]

Majer and Svoboda, 1985
Majer, V.; Svoboda, V., Enthalpies of Vaporization of Organic Compounds: A Critical Review and Data Compilation, Blackwell Scientific Publications, Oxford, 1985, 300. [all data]

Svoboda, 1998
Svoboda, V., Enthalpies of vaporization, and the cohesive and internal energies of 2,2-dimethylpentane, 2,4-dimethylpentane, 2,2,3-trimethylpentane, 2,3,3-trimethylpentane, and 3-ethylpentane, The Journal of Chemical Thermodynamics, 1998, 30, 11, 1411-1417, https://doi.org/10.1006/jcht.1998.0414 . [all data]

Osborne and Ginnings, 1947
Osborne, Nathan S.; Ginnings, Defoe C., Measurements of heat of vaporization and heat capacity of a number of hydrocarbons, J. RES. NATL. BUR. STAN., 1947, 39, 5, 453-17, https://doi.org/10.6028/jres.039.031 . [all data]

Osborne and Ginnings, 1947, 2
Osborne, N.S.; Ginnings, D.C., Measurements of heat of vaporization and heat capacity of a number of hydrocarbons, J. Res. NBS, 1947, 39, 453-477. [all data]

Aldrich Chemical Company Inc., 1990
Aldrich Chemical Company Inc., Catalog Handbook of Fine Chemicals, Aldrich Chemical Company, Inc., Milwaukee WI, 1990, 1. [all data]

Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw, Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2 . [all data]

Forziati, Norris, et al., 1949
Forziati, Alphonse F.; Norris, William R.; Rossini, Frederick D., Vapor pressures and boiling points of sixty API-NBS hydrocarbons, J. RES. NATL. BUR. STAN., 1949, 43, 6, 555-17, https://doi.org/10.6028/jres.043.050 . [all data]

Willingham, Taylor, et al., 1945
Willingham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor pressures and boiling points of some paraffin, alkylcyclopentane, alkylcyclohexane, and alkylbenzene hydrocarbons, J. RES. NATL. BUR. STAN., 1945, 35, 3, 219-17, https://doi.org/10.6028/jres.035.009 . [all data]

Williamham, Taylor, et al., 1945
Williamham, C.B.; Taylor, W.J.; Pignocco, J.M.; Rossini, F.D., Vapor Pressures and Boiling Points of Some Paraffin, Alkylcyclopentane, Alkylcyclohexane, and Alkylbenzene Hydrocarbons, J. Res. Natl. Bur. Stand. (U.S.), 1945, 35, 3, 219-244, https://doi.org/10.6028/jres.035.009 . [all data]

Acree, 1991
Acree, William E., Thermodynamic properties of organic compounds: enthalpy of fusion and melting point temperature compilation, Thermochimica Acta, 1991, 189, 1, 37-56, https://doi.org/10.1016/0040-6031(91)87098-H . [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, References