Pentane, 2,2-dimethyl-
- Formula: C7H16
- Molecular weight: 100.2019
- IUPAC Standard InChIKey: CXOWYJMDMMMMJO-UHFFFAOYSA-N
- CAS Registry Number: 590-35-2
- 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. - Other names: 2,2-Dimethylpentane
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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 |
---|---|---|---|---|---|
ΔfH°gas | -49.29 ± 0.32 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
ΔfH°gas | -50.07 | kcal/mol | N/A | Davies and Gilbert, 1941 | Value 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 |
S°gas | 93.901 | cal/mol*K | N/A | Huffman H.M., 1961 | GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
27.930 | 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 good agreement with experimental data available for alkanes. However, large uncertainties could be expected at high temperatures.; GT |
36.790 | 273.15 | ||
39.84 ± 0.1 | 298.15 | ||
40.069 | 300. | ||
51.809 | 400. | ||
62.089 | 500. | ||
70.901 | 600. | ||
78.401 | 700. | ||
84.900 | 800. | ||
90.600 | 900. | ||
95.600 | 1000. | ||
100.00 | 1100. | ||
103.90 | 1200. | ||
107.00 | 1300. | ||
111.00 | 1400. | ||
114.00 | 1500. |
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 |
---|---|---|---|---|---|
ΔfH°liquid | -57.05 ± 0.32 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
ΔfH°liquid | -57.9 ± 0.3 | kcal/mol | Ccb | Davies and Gilbert, 1941 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
ΔcH°liquid | -1147.85 ± 0.30 | kcal/mol | Ccb | Prosen and Rossini, 1945 | Corresponding ΔfHºliquid = -57.03 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
ΔcH°liquid | -1146.9 ± 0.3 | kcal/mol | Ccb | Davies and Gilbert, 1941 | Corresponding ΔfHºliquid = -58.02 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°liquid | 71.771 | cal/mol*K | N/A | Huffman, Gross, et al., 1961 | DH |
S°liquid | 68.09 | cal/mol*K | N/A | Huffman, Parks, et al., 1930 | Extrapolation below 90 K, 64.10 J/mol*K.; DH |
Constant pressure heat capacity of liquid
Cp,liquid (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
52.849 | 298.15 | Huffman, Gross, et al., 1961 | T = 10 to 300 K.; DH |
51.89 | 294.1 | Huffman, Parks, et al., 1930 | T = 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 |
---|---|---|---|---|---|
Tboil | 352.3 ± 0.3 | K | AVG | N/A | Average of 48 out of 53 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 149. ± 2. | K | AVG | N/A | Average of 20 out of 22 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 149.2 ± 0.9 | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 520.5 ± 0.5 | K | N/A | Daubert, 1996 | |
Tc | 520.44 | K | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4 K; TRC |
Tc | 520.85 | K | N/A | Edgar and Calingaert, 1929 | Uncertainty assigned by TRC = 0.5 K; measured by Keys and Kleinschmidt; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 27.3 ± 0.5 | atm | N/A | Daubert, 1996 | |
Pc | 27.367 | atm | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.4000 atm; TRC |
Pc | 28.4000 | atm | N/A | Edgar and Calingaert, 1929 | Uncertainty assigned by TRC = 0.5000 atm; measured by Keys and Kleinschmidt; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.416 | l/mol | N/A | Daubert, 1996 | |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.41 ± 0.05 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.41 | mol/l | N/A | McMicking and Kay, 1965 | Uncertainty assigned by TRC = 0.05 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 7.782 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 7.74 ± 0.02 | kcal/mol | C | Svoboda, 1998 | AC |
ΔvapH° | 7.74 ± 0.02 | kcal/mol | C | Osborne and Ginnings, 1947 | AC |
ΔvapH° | 7.70 ± 0.02 | kcal/mol | C | Osborne and Ginnings, 1947 | AC |
ΔvapH° | 7.749 | kcal/mol | C | Osborne and Ginnings, 1947, 2 | ALS |
Reduced pressure boiling point
Tboil (K) | Pressure (atm) | Reference | Comment |
---|---|---|---|
351.2 | 0.978 | Aldrich Chemical Company Inc., 1990 | BS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
6.986 | 352.4 | N/A | Majer and Svoboda, 1985 | |
7.60 ± 0.02 | 308. | C | Svoboda, 1998 | AC |
7.50 ± 0.02 | 315. | C | Svoboda, 1998 | AC |
7.41 ± 0.02 | 323. | C | Svoboda, 1998 | AC |
7.29 ± 0.02 | 330. | C | Svoboda, 1998 | AC |
7.19 ± 0.02 | 338. | C | Svoboda, 1998 | AC |
7.03 ± 0.02 | 348. | C | Svoboda, 1998 | AC |
6.88 ± 0.02 | 358. | C | Svoboda, 1998 | AC |
6.72 ± 0.02 | 368. | C | Svoboda, 1998 | AC |
7.93 | 292. | A | Stephenson and Malanowski, 1987 | Based on data from 277. to 354. K.; AC |
7.19 | 368. | A | Stephenson and Malanowski, 1987 | Based on data from 353. to 483. K.; AC |
7.84 | 300. | N/A | Forziati, Norris, et al., 1949 | Based on data from 285. to 353. K.; AC |
7.79 | 303. | MM | Willingham, Taylor, et al., 1945 | Based on data from 288. to 353. K.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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Temperature (K) | A | B | C | Reference |
---|---|---|---|---|
288.47 to 353.20 | 3.93428 | 1190.298 | -49.807 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.392 | 149.43 | Huffman, Gross, et al., 1961 | DH |
1.40 | 148.1 | Acree, 1991 | AC |
1.401 | 148.1 | Huffman, Parks, et al., 1930 | DH |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
9.316 | 149.43 | Huffman, Gross, et al., 1961 | DH |
9.460 | 148.1 | Huffman, Parks, et al., 1930 | DH |
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
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Cp,liquid Constant pressure heat capacity of liquid Pc Critical pressure S°gas Entropy of gas at standard conditions S°liquid Entropy of liquid at standard conditions Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔcH°liquid Enthalpy of combustion of liquid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions ΔfH°liquid Enthalpy of formation of liquid at standard conditions ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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