Butane, 2,2-dimethyl-
- Formula: C6H14
- Molecular weight: 86.1754
- IUPAC Standard InChIKey: HNRMPXKDFBEGFZ-UHFFFAOYSA-N
- CAS Registry Number: 75-83-2
- 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: Neohexane; 2,2-Dimethylbutane; (CH3)3CCH2CH3; UN 1208
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Gas phase thermochemistry data
Go To: Top, Phase change data, Mass spectrum (electron ionization), 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
GT - Glushko Thermocenter, Russian Academy of Sciences, Moscow
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -44.35 ± 0.23 | kcal/mol | Ccb | Prosen and Rossini, 1945 | ALS |
Quantity | Value | Units | Method | Reference | Comment |
S°gas | 85.72 ± 0.20 | cal/mol*K | N/A | Kilpatrick J.E., 1946 | The entropy values S(296.05 K)=357.19 and S(322.85 K)=369.87 J/mol*K were calculated by [ Scott D.W., 1974] from the experimental data [ Douslin D.R., 1946].; GT |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
24.250 | 200. | Scott D.W., 1974, 2 | Recommended values were obtained from the consistent correlation scheme for alkanes [ Scott D.W., 1974, Scott D.W., 1974, 2]. This approach gives a better agreement with experimental data than the statistical thermodynamics calculation [ Pitzer K.S., 1946] (see also [ Waddington G., 1949]).; GT |
31.329 | 273.15 | ||
33.81 ± 0.07 | 298.15 | ||
34.001 | 300. | ||
43.769 | 400. | ||
52.660 | 500. | ||
60.500 | 600. | ||
67.299 | 700. | ||
73.301 | 800. | ||
78.499 | 900. | ||
83.200 | 1000. | ||
87.299 | 1100. | ||
90.901 | 1200. | ||
94.001 | 1300. | ||
97.000 | 1400. | ||
100.00 | 1500. |
Constant pressure heat capacity of gas
Cp,gas (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
38.100 ± 0.076 | 341.55 | Waddington G., 1947 | GT |
39.250 ± 0.079 | 353.20 | ||
41.501 ± 0.084 | 376.05 | ||
44.950 ± 0.091 | 412.40 | ||
48.329 ± 0.096 | 449.40 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Mass spectrum (electron ionization), 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
CAL - James S. Chickos, William E. Acree, Jr., Joel F. Liebman, Students of Chem 202 (Introduction to the Literature of Chemistry), University of Missouri -- St. Louis
DH - Eugene S. Domalski and Elizabeth D. Hearing
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 322.9 ± 0.1 | K | AVG | N/A | Average of 46 out of 54 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 173. ± 2. | K | AVG | N/A | Average of 24 out of 28 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 174. ± 2. | K | AVG | N/A | Average of 6 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 489.0 ± 0.5 | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 30.6 ± 0.2 | atm | N/A | Daubert, 1996 | |
Pc | 30.6179 | atm | N/A | Genco, Teja, et al., 1980 | Uncertainty assigned by TRC = 0.05 atm; TRC |
Pc | 30.61 | atm | N/A | Kay and Young, 1975 | Uncertainty assigned by TRC = 0.03 atm; TRC |
Pc | 30.6700 | atm | N/A | Kay, 1946 | Uncertainty assigned by TRC = 0.09998 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.358 | l/mol | N/A | Daubert, 1996 | |
Vc | 0.358 | l/mol | N/A | Genco, Teja, et al., 1980 | Uncertainty assigned by TRC = 0.001 l/mol; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 2.80 ± 0.02 | mol/l | N/A | Daubert, 1996 | |
ρc | 2.79 | mol/l | N/A | Kay, 1946 | Uncertainty assigned by TRC = 0.02 mol/l; by extrapolation of rectilinear diameter to Tc; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 6.675 | kcal/mol | N/A | Majer and Svoboda, 1985 | |
ΔvapH° | 6.62 | kcal/mol | N/A | Reid, 1972 | AC |
ΔvapH° | 6.616 | kcal/mol | C | Osborne and Ginnings, 1947 | ALS |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
6.288 | 322.9 | N/A | Majer and Svoboda, 1985 | |
6.86 | 288. | N/A | Nicolini and Laffitte, 1949 | Based on data from 273. to 318. K. See also Boublik, Fried, et al., 1984.; AC |
6.64 ± 0.02 | 296. | C | Waddington and Douslin, 1947 | AC |
6.29 ± 0.02 | 323. | C | Waddington and Douslin, 1947 | AC |
6.98 | 274. | N/A | Kilpatrick and Pitzer, 1946 | Based on data from 211. to 289. K.; AC |
6.76 | 303. | MM | Willingham, Taylor, et al., 1945 | Based on data from 288. to 323. K.; AC |
Enthalpy of vaporization
ΔvapH =
A exp(-βTr) (1 − Tr)β
ΔvapH =
Enthalpy of vaporization (at saturation pressure)
(kcal/mol)
Tr = reduced temperature (T / Tc)
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Temperature (K) | A (kcal/mol) | β | Tc (K) | Reference | Comment |
---|---|---|---|---|---|
296. to 323. | 10.02 | 0.2675 | 488.7 | Majer and Svoboda, 1985 |
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 | Comment |
---|---|---|---|---|---|
210.99 to 289.38 | 3.7325 | 1022.204 | -49.529 | Kilpatrick and Pitzer, 1946 | Coefficents calculated by NIST from author's data. |
288.53 to 323.68 | 3.87402 | 1081.176 | -43.807 | Williamham, Taylor, et al., 1945 |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
0.14 | 174.3 | Domalski and Hearing, 1996 | AC |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
10.17 | 126.8 | Domalski and Hearing, 1996 | CAL |
0.483 | 140.8 | ||
0.791 | 174.3 |
Enthalpy of phase transition
ΔHtrs (kcal/mol) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
1.293 | 126.81 | crystaline, III | crystaline, II | Douslin and Huffman, 1946 | DH |
0.06819 | 140.79 | crystaline, II | crystaline, I | Douslin and Huffman, 1946 | DH |
0.1384 | 174.28 | crystaline, I | liquid | Douslin and Huffman, 1946 | DH |
1.289 | 126.81 | crystaline, III | crystaline, II | Kilpatrick and Pitzer, 1946 | DH |
0.0676 | 140.88 | crystaline, II | crystaline, I | Kilpatrick and Pitzer, 1946 | DH |
0.138 | 174.66 | crystaline, I | liquid | Kilpatrick and Pitzer, 1946 | DH |
1.095 | 127.11 | crystaline, II | crystaline, I | Stull, 1937 | DH |
0.111 | 172.13 | crystaline, I | liquid | Stull, 1937 | DH |
Entropy of phase transition
ΔStrs (cal/mol*K) | Temperature (K) | Initial Phase | Final Phase | Reference | Comment |
---|---|---|---|---|---|
10.20 | 126.81 | crystaline, III | crystaline, II | Douslin and Huffman, 1946 | DH |
0.485 | 140.79 | crystaline, II | crystaline, I | Douslin and Huffman, 1946 | DH |
0.793 | 174.28 | crystaline, I | liquid | Douslin and Huffman, 1946 | DH |
10.2 | 126.81 | crystaline, III | crystaline, II | Kilpatrick and Pitzer, 1946 | DH |
0.480 | 140.88 | crystaline, II | crystaline, I | Kilpatrick and Pitzer, 1946 | DH |
0.796 | 174.66 | crystaline, I | liquid | Kilpatrick and Pitzer, 1946 | DH |
8.614 | 127.11 | crystaline, II | crystaline, I | Stull, 1937 | DH |
0.645 | 172.13 | crystaline, I | liquid | Stull, 1937 | DH |
Mass spectrum (electron ionization)
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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director
Spectrum
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Additional Data
View image of digitized spectrum (can be printed in landscape orientation).
Due to licensing restrictions, this spectrum cannot be downloaded.
Owner | NIST Mass Spectrometry Data Center Collection (C) 2014 copyright by the U.S. Secretary of Commerce on behalf of the United States of America. All rights reserved. |
---|---|
Origin | Japan AIST/NIMC Database- Spectrum MS-NW-1294 |
NIST MS number | 227826 |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), 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]
Kilpatrick J.E., 1946
Kilpatrick J.E.,
The thermodynamics of 2,2-dimethylbutane, including the heat capacity, heats of transition, fusion and vaporization and the entropy,
J. Am. Chem. Soc., 1946, 68, 1066-1072. [all data]
Scott D.W., 1974
Scott D.W.,
Correlation of the chemical thermodynamic properties of alkane hydrocarbons,
J. Chem. Phys., 1974, 60, 3144-3165. [all data]
Douslin D.R., 1946
Douslin D.R.,
Low-temperature thermal data on the five isomeric hexanes,
J. Am. Chem. Soc., 1946, 68, 1704-1708. [all data]
Scott D.W., 1974, 2
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]
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., 1949
Waddington G.,
Experimental vapor heat capacities and heats of vaporization of 2-methylpentane, 3-methylpentane, and 2,3-dimethylbutane,
J. Am. Chem. Soc., 1949, 71, 3902-3906. [all data]
Waddington G., 1947
Waddington G.,
Experimental vapor heat capacities and heats of vaporization of n-hexane and 2,2-dimethylbutane,
J. Am. Chem. Soc., 1947, 69, 2275-2279. [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]
Genco, Teja, et al., 1980
Genco, J.M.; Teja, A.S.; Kay, W.B.,
Study of the critical and azeotropic behavior of binary mixtures I critical states of perfluoromethylcyclohexane + isomeric hexane systems,
J. Chem. Eng. Data, 1980, 25, 350. [all data]
Kay and Young, 1975
Kay, W.B.; Young, C.L.,
Gas-liquid critical properties. Tetradecafluoromethylcyclohexane( perfluoromethylcyclohexane)-2,2-dimethylbutane,
Int. DATA Ser., Sel. Data Mixtures, Ser. A, 1975, No. 1, 58. [all data]
Kay, 1946
Kay, W.B.,
The Vapor Pressures and Saturated Liquid and Vapor Densities of the Isomeric Hexanes,
J. Am. Chem. Soc., 1946, 68, 1336. [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]
Reid, 1972
Reid, Robert C.,
Handbook on vapor pressure and heats of vaporization of hydrocarbons and related compounds, R. C. Wilhort and B. J. Zwolinski, Texas A Research Foundation. College Station, Texas(1971). 329 pages.$10.00,
AIChE J., 1972, 18, 6, 1278-1278, https://doi.org/10.1002/aic.690180637
. [all data]
Osborne and Ginnings, 1947
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]
Nicolini and Laffitte, 1949
Nicolini, E.; Laffitte, P.,
Compt. Rend., 1949, 229, 757. [all data]
Boublik, Fried, et al., 1984
Boublik, T.; Fried, V.; Hala, E.,
The Vapour Pressures of Pure Substances: Selected Values of the Temperature Dependence of the Vapour Pressures of Some Pure Substances in the Normal and Low Pressure Region, 2nd ed., Elsevier, New York, 1984, 972. [all data]
Waddington and Douslin, 1947
Waddington, Guy; Douslin, Donald R.,
Experimental Vapor Heat Capacities and Heats of Vaporization of n-Hexane and 2,2-Dimethylbutane 1,
J. Am. Chem. Soc., 1947, 69, 10, 2275-2279, https://doi.org/10.1021/ja01202a011
. [all data]
Kilpatrick and Pitzer, 1946
Kilpatrick, J.E.; Pitzer, K.S.,
The thermodynamics of 2,2-dimethylbutane, including the heat capacity, heats of transitions, fusion and vaporization and the entropy,
J. Am. Chem. Soc., 1946, 68, 1066-1072. [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]
Domalski and Hearing, 1996
Domalski, Eugene S.; Hearing, Elizabeth D.,
Heat Capacities and Entropies of Organic Compounds in the Condensed Phase. Volume III,
J. Phys. Chem. Ref. Data, 1996, 25, 1, 1, https://doi.org/10.1063/1.555985
. [all data]
Douslin and Huffman, 1946
Douslin, D.R.; Huffman, H.M.,
Low-temperature thermal data on the five isometric hexanes,
J. Am. Chem. Soc., 1946, 68, 1704-1708. [all data]
Stull, 1937
Stull, D.R.,
A semi-micro calorimeter for measuring heat capacities at low temperatures,
J. Am. Chem. Soc., 1937, 59, 2726-2733. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Mass spectrum (electron ionization), References
- Symbols used in this document:
Cp,gas Constant pressure heat capacity of gas Pc Critical pressure S°gas Entropy of gas at standard conditions Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔHtrs Enthalpy of phase transition ΔStrs Entropy of phase transition ΔfH°gas Enthalpy of formation of gas 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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