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Isobutane

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Gas phase thermochemistry data

Go To: Top, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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
Deltafgas-134.2 ± 0.63kJ/molCcbPittam and Pilcher, 1972ALS
Deltafgas-135.6 ± 0.54kJ/molCmProsen, Maron, et al., 1951see Prosen and Rossini, 1945, Rossini, 1935; ALS
Quantity Value Units Method Reference Comment
Deltacgas-2869.0 ± 0.59kJ/molCcbPittam and Pilcher, 1972Corresponding «DELTA»fgas = -134.2 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Deltacgas-2867.6 ± 0.46kJ/molCmProsen, Maron, et al., 1951see Prosen and Rossini, 1945, Rossini, 1935; Corresponding «DELTA»fgas = -135.6 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of gas

Cp,gas (J/mol*K) Temperature (K) Reference Comment
34.8150.Chen S.S., 1975Recommended values are in good agreement with those calculated by [ Pitzer K.S., 1946].; GT
47.28100.
60.29150.
71.84200.
89.91273.15
96.65298.15
97.15300.
124.43400.
149.24500.
170.37600.
188.28700.
203.64800.
216.94900.
228.451000.
238.491100.
247.151200.
254.721300.
261.291400.
267.021500.

Constant pressure heat capacity of gas

Cp,gas (J/mol*K) Temperature (K) Reference Comment
82.30 ± 0.06243.15Ernst G., 1970Other experimental values of heat capacity [ Sage B.H., 1937, Sage B.H., 1938] are less accurate, see [ Chen S.S., 1975]. Please also see Dailey B.P., 1943, Wacker P.F., 1947.; GT
89.97 ± 0.06273.15
95.21 ± 0.10293.15
100.67 ± 0.10313.15
106.37 ± 0.11333.15
109.66347.6
111.74 ± 0.11353.15
112.55359.4
119.62387.5
137.03452.5
152.93520.9
161.29561.7
169.70605.3
185.18692.7

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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 by: Eugene S. Domalski and Elizabeth D. Hearing

Quantity Value Units Method Reference Comment
liquid200.79J/mol*KN/AAston, Kennedy, et al., 1940 
liquid198.7J/mol*KN/AParks, Shomate, et al., 1937Extrapolation below 67 K, 44.02 J/mol*K.

Constant pressure heat capacity of liquid

Cp,liquid (J/mol*K) Temperature (K) Reference Comment
129.70260.Aston, Kennedy, et al., 1940T = 20 to 260 K.
128.4258.3Parks, Shomate, et al., 1937T = 79 to 261 K. Value is unsmoothed experimental datum.

Phase change data

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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, Kenneth Kroenlein director
DH - Eugene S. Domalski and Elizabeth D. Hearing
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Quantity Value Units Method Reference Comment
Tboil262. ± 2.KAVGN/AAverage of 24 out of 25 values; Individual data points
Quantity Value Units Method Reference Comment
Tfus140. ± 100.KAVGN/AAverage of 7 values; Individual data points
Quantity Value Units Method Reference Comment
Ttriple113.55KN/AYounglove and Ely, 1987Uncertainty assigned by TRC = 0.05 K; TRC
Ttriple113.55KN/AGoodwin and Haynes, 1982Uncertainty assigned by TRC = 0.02 K; TRC
Ttriple113.74KN/AAston, Kennedy, et al., 1940, 2Uncertainty assigned by TRC = 0.07 K; TRC
Ttriple113.2KN/AParks, Shomate, et al., 1937, 2Uncertainty assigned by TRC = 0.2 K; TRC
Quantity Value Units Method Reference Comment
Ptriple1.9481×10-7barN/AYounglove and Ely, 1987Uncertainty assigned by TRC = 2.×10-10 bar; TRC
Ptriple1.9481×10-7barN/AGoodwin and Haynes, 1982Uncertainty assigned by TRC = 5.×10-10 bar; TRC
Quantity Value Units Method Reference Comment
Tc407.7 ± 0.8KAVGN/AAverage of 10 values; Individual data points
Quantity Value Units Method Reference Comment
Pc36.5 ± 0.5barAVGN/AAverage of 9 values; Individual data points
Quantity Value Units Method Reference Comment
Vc0.259l/molN/ADaubert, 1996 
Vc0.2591l/molN/AYounglove and Ely, 1987Uncertainty assigned by TRC = 0.001 l/mol; TRC
Quantity Value Units Method Reference Comment
rhoc3.85 ± 0.05mol/lN/ADaubert, 1996 
rhoc3.880mol/lN/ALevelt Sengers, Kamgar-Parsi, et al., 1983Uncertainty assigned by TRC = 0.009 mol/l; TRC
rhoc3.91mol/lN/AWaxman and Gallagher, 1983Uncertainty assigned by TRC = 0.09 mol/l; TRC
rhoc3.8601mol/lN/AGoodwin and Haynes, 1982Uncertainty assigned by TRC = 0.03 mol/l; TRC
rhoc3.802mol/lN/ABeattie, Edwards, et al., 1949Uncertainty assigned by TRC = 0.1 mol/l; TRC
Quantity Value Units Method Reference Comment
Deltavap19.99kJ/molN/AMajer and Svoboda, 1985 

Enthalpy of vaporization

DeltavapH (kJ/mol) Temperature (K) Method Reference Comment
21.297261.44N/AAston, Kennedy, et al., 1940P = 101.325 kPa; DH
21.3261.3N/AMajer and Svoboda, 1985 
21.5318.N/ALim, Park, et al., 1999Based on data from 303. - 333. K.; AC
22.4265.AStephenson and Malanowski, 1987Based on data from 186. - 280. K.; AC
26.9172.AStephenson and Malanowski, 1987Based on data from 121. - 187. K.; AC
21.9278.AStephenson and Malanowski, 1987Based on data from 263. - 306. K.; AC
21.4316.AStephenson and Malanowski, 1987Based on data from 301. - 366. K.; AC
21.6376.AStephenson and Malanowski, 1987Based on data from 361. - 408. K.; AC
21.6292.N/ASteele, Poling, et al., 1976Based on data from 277. - 344. K. See also Boublik, Fried, et al., 1984.; AC
21.3286.N/AReid, 1972AC
21. ± 3.261.44VAston, Kennedy, et al., 1940, 3ALS
22.6247.N/AAston, Kennedy, et al., 1940Based on data from 188. - 262. K. See also Boublik, Fried, et al., 1984.; AC

Entropy of vaporization

DeltavapS (J/mol*K) Temperature (K) Reference Comment
81.46261.44Aston, Kennedy, et al., 1940P; DH

Antoine Equation Parameters

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

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Temperature (K) A B C Reference Comment
261.31 - 408.124.32811132.1080.918Das, Reed, et al., 1973Coefficents calculated by NIST from author's data.
188.06 - 261.543.94417912.141-29.808Aston, Kennedy, et al., 1940Coefficents calculated by NIST from author's data.

Enthalpy of fusion

DeltafusH (kJ/mol) Temperature (K) Reference Comment
4.540113.74Aston, Kennedy, et al., 1940DH
4.49113.7Perkins and Magee, 2009AC
4.56113.7Domalski and Hearing, 1996AC
4.498113.2Parks, Shomate, et al., 1937DH

Entropy of fusion

DeltafusS (J/mol*K) Temperature (K) Reference Comment
39.92113.74Aston, Kennedy, et al., 1940DH
39.73113.2Parks, Shomate, et al., 1937DH

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:


Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, IR Spectrum, 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:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

C4H9- + Hydrogen cation = Isobutane

By formula: C4H9- + H+ = C4H10

Quantity Value Units Method Reference Comment
Deltar1728. ± 8.4kJ/molBranDePuy, Gronert, et al., 1989gas phase; B
Deltar1735. ± 20.kJ/molBranPeerboom, Rademaker, et al., 1992gas phase; B
Quantity Value Units Method Reference Comment
Deltar1692. ± 8.8kJ/molH-TSDePuy, Gronert, et al., 1989gas phase; B
Deltar1699. ± 21.kJ/molH-TSPeerboom, Rademaker, et al., 1992gas phase; B

C4H9- + Hydrogen cation = Isobutane

By formula: C4H9- + H+ = C4H10

Quantity Value Units Method Reference Comment
Deltar1728. ± 8.4kJ/molBranDePuy, Gronert, et al., 1989gas phase; B
Deltar1732. ± 8.4kJ/molBranDePuy, Bierbaum, et al., 1984gas phase; B
Quantity Value Units Method Reference Comment
Deltar1697. ± 8.8kJ/molH-TSDePuy, Gronert, et al., 1989gas phase; B

1-Propene, 2-methyl- + Hydrogen = Isobutane

By formula: C4H8 + H2 = C4H10

Quantity Value Units Method Reference Comment
Deltar-117.8 ± 0.42kJ/molChydKistiakowsky, Ruhoff, et al., 1935gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -118.78 ± 0.75 kJ/mol; At 355 °K; ALS

Butane = Isobutane

By formula: C4H10 = C4H10

Quantity Value Units Method Reference Comment
Deltar-9.699kJ/molEqkPines, Kvetinskas, et al., 1945gas phase; Heat of isomerization; ALS

IR Spectrum

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, Mass spectrum (electron ionization), References, Notes

Data compiled by: Coblentz Society, Inc.

Data compiled by: NIST Mass Spectrometry Data Center, William E. Wallace, director


Mass spectrum (electron ionization)

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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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Mass spectrum
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Additional Data

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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.
NIST MS number 121

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References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, 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.

Pittam and Pilcher, 1972
Pittam, D.A.; Pilcher, G., Measurements of heats of combustion by flame calorimetry. Part 8.-Methane, ethane, propane, n-butane and 2-methylpropane, J. Chem. Soc. Faraday Trans. 1, 1972, 68, 2224-2229. [all data]

Prosen, Maron, et al., 1951
Prosen, E.J.; Maron, F.W.; Rossini, F.D., Heats of combustion, formation, and insomerization of ten C4 hydrocarbons, J. Res. NBS, 1951, 46, 106-112. [all data]

Prosen and Rossini, 1945
Prosen, E.J.; Rossini, F.D., Heats of formation and combustion of 1,3-butadiene and styrene, J. Res. NBS, 1945, 34, 59-63. [all data]

Rossini, 1935
Rossini, F.D., Heat of combustion of isobutane, J. Res. NBS, 1935, 15, 357-361. [all data]

Chen S.S., 1975
Chen S.S., Ideal gas thermodynamic properties and isomerization of n-butane and isobutane, J. Phys. Chem. Ref. Data, 1975, 4, 859-869. [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]

Ernst G., 1970
Ernst G., Ideal and real gas state heat capacities Cp of C3H8, i-C4H10, C2F5Cl, CH2ClCF3, CF2ClCFCl2, and CHF2Cl, J. Chem. Thermodyn., 1970, 2, 787-791. [all data]

Sage B.H., 1937
Sage B.H., Phase equilibria in hydrocarbon systems. XX. Isobaric heat capacity of gaseous propane, n-butane, isobutane, and n-pentane, Ind. Eng. Chem., 1937, 29, 1309-1314. [all data]

Sage B.H., 1938
Sage B.H., Phase equilibrium in hydrocarbon systems. Thermodynamic properties of isobutane, Ind. Eng. Chem., 1938, 30, 673-681. [all data]

Dailey B.P., 1943
Dailey B.P., Heat capacities and hindered rotation in n-butane and isobutane, J. Am. Chem. Soc., 1943, 65, 44-46. [all data]

Wacker P.F., 1947
Wacker P.F., Heat capacities of gaseous oxygen, isobutane, and 1-butene from -30 to +90 C, J. Res. Nat. Bur. Stand., 1947, 38, 651-659. [all data]

Aston, Kennedy, et al., 1940
Aston, J.G.; Kennedy, R.M.; Schumann, S.C., The heat capacity and entropy, heats of fusion and vaporization and the vapor pressure of isobutane, J. Am. Chem. Soc., 1940, 62, 2059-2063. [all data]

Parks, Shomate, et al., 1937
Parks, G.S.; Shomate, C.H.; Kennedy, W.D.; Crawford, B.L., Jr., The entropies of n-butane and isobutane, with some heat capacity data for isobutane, J. Chem. Phys., 1937, 5, 359-363. [all data]

Younglove and Ely, 1987
Younglove, B.A.; Ely, J.F., Thermophysical Properties of Fluids II. Methane, Ethane, Propane, Isobutane, and Normal Butane, J. Phys. Chem. Ref. Data, 1987, 16, 577. [all data]

Goodwin and Haynes, 1982
Goodwin, R.D.; Haynes, W.M., Thermophysical Properties of Propane from 85 to 700 K at Pressures to 70 MPa, NBS Monogr. (U. S.) No. 170, 249 pp., 1982. [all data]

Aston, Kennedy, et al., 1940, 2
Aston, J.G.; Kennedy, R.M.; Schumann, S.C., The Heat Capacity and Entropy of Fusion and Vaporization and the Vapor Pressure of Isobutane, J. Am. Chem. Soc., 1940, 62, 2059. [all data]

Parks, Shomate, et al., 1937, 2
Parks, G.S.; Shomate, C.H.; Kennedy, W.D.; Crawford, B.L., The entropies of n-butane and isobutane with some heat capacity data for isobutane, J. Chem. Phys., 1937, 5, 359-63. [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]

Levelt Sengers, Kamgar-Parsi, et al., 1983
Levelt Sengers, J.M.H.; Kamgar-Parsi, B.; Sengers, J.V., Thermodnamic Properties of Isobutane in the Critical Region, J. Chem. Eng. Data, 1983, 28, 354-362. [all data]

Waxman and Gallagher, 1983
Waxman, M.; Gallagher, J.S., Thermodynamic Properties of Isobutane for Temperatures from 250 to 600 K and Pressures from 0.1 to 40 MPa, J. Chem. Eng. Data, 1983, 28, 224. [all data]

Beattie, Edwards, et al., 1949
Beattie, J.A.; Edwards, D.G.; Marple, S., The Vapor Pressure, Orthobaric Liquid Density, and Critical Constants of Isobutane, J. Chem. Phys., 1949, 17, 576. [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]

Lim, Park, et al., 1999
Lim, Jong Sung; Park, Ji-Young; Lee, Byung-Gwon; Lee, Youn-Woo; Kim, Jae-Duck, Phase Equilibria of CFC Alternative Refrigerant Mixtures: Binary Systems of Isobutane + 1,1,1,2-Tetrafluoroethane, + 1,1-Difluoroethane, and + Difluoromethane, J. Chem. Eng. Data, 1999, 44, 6, 1226-1230, https://doi.org/10.1021/je9900777 . [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]

Steele, Poling, et al., 1976
Steele, Kevin; Poling, Bruce E.; Manley, David B., Vapor pressures for the system 1-butene, isobutane, and 1,3-butadiene, J. Chem. Eng. Data, 1976, 21, 4, 399-403, https://doi.org/10.1021/je60071a006 . [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]

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]

Aston, Kennedy, et al., 1940, 3
Aston, J.G.; Kennedy, R.M.; Schumann, S.C., The heat capacity and entropy, heats of fusion and vaporization and the vapor pressure of isobutane, J. Am. Chem. Soc., 1940, 62, 2059-20. [all data]

Das, Reed, et al., 1973
Das, T.R.; Reed, C.O., Jr.; Eubank, P.T., PVT Surface and Thermodynamic Properties of Isobutane, J. Chem. Eng. Data, 1973, 18, 3, 253-262, https://doi.org/10.1021/je60058a001 . [all data]

Perkins and Magee, 2009
Perkins, Richard A.; Magee, Joseph W., Molar Heat Capacity at Constant Volume for Isobutane at Temperatures from (114 to 345) K and at Pressures to 35 MPa «8224» «8225», J. Chem. Eng. Data, 2009, 54, 9, 2646-2655, https://doi.org/10.1021/je9001575 . [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]

DePuy, Gronert, et al., 1989
DePuy, C.H.; Gronert, S.; Barlow, S.E.; Bierbaum, V.M.; Damrauer, R., The Gas Phase Acidities of the Alkanes, J. Am. Chem. Soc., 1989, 111, 6, 1968, https://doi.org/10.1021/ja00188a003 . [all data]

Peerboom, Rademaker, et al., 1992
Peerboom, R.A.L.; Rademaker, G.J.; Dekoning, L.J.; Nibbering, N.M.M., Stabilization of Cycloalkyl Carbanions in the Gas Phase, Rapid Commun. Mass Spectrom., 1992, 6, 6, 394, https://doi.org/10.1002/rcm.1290060608 . [all data]

DePuy, Bierbaum, et al., 1984
DePuy, C.H.; Bierbaum, V.M.; Damrauer, R., Relative Gas-Phase Acidities of the Alkanes, J. Am. Chem. Soc., 1984, 106, 4051. [all data]

Kistiakowsky, Ruhoff, et al., 1935
Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E., Heats of organic reactions. II. Hydrogenation of some simpler olefinic hydrocarbons, J. Am. Chem. Soc., 1935, 57, 876-882. [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press, New York, 1970, 1-636. [all data]

Pines, Kvetinskas, et al., 1945
Pines, H.; Kvetinskas, B.; Kassel, L.S.; Ipatieff, V.N., Determination of equilibrium constants for butanes and pentanes, J. Am. Chem. Soc., 1945, 67, 631-637. [all data]


Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), References