Isobutane
- Formula: C4H10
- Molecular weight: 58.1222
- IUPAC Standard InChIKey: NNPPMTNAJDCUHE-UHFFFAOYSA-N
- CAS Registry Number: 75-28-5
- 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: Propane, 2-methyl-; Trimethylmethane; 1,1-Dimethylethane; 2-Methylpropane; iso-C4H10; i-Butane; UN 1969; R 600a; tert-Butane; A 31; Methylpropane; A 31 (hydrocarbon)
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Phase change data
Go To: Top, 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
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 |
---|---|---|---|---|---|
Tboil | 262. ± 2. | K | AVG | N/A | Average of 24 out of 25 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 140. ± 100. | K | AVG | N/A | Average of 7 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 113.55 | K | N/A | Younglove and Ely, 1987 | Uncertainty assigned by TRC = 0.05 K; TRC |
Ttriple | 113.55 | K | N/A | Goodwin and Haynes, 1982 | Uncertainty assigned by TRC = 0.02 K; TRC |
Ttriple | 113.74 | K | N/A | Aston, Kennedy, et al., 1940 | Uncertainty assigned by TRC = 0.07 K; TRC |
Ttriple | 113.2 | K | N/A | Parks, Shomate, et al., 1937 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ptriple | 1.9226×10-7 | atm | N/A | Younglove and Ely, 1987 | Uncertainty assigned by TRC = 2.×10-10 atm; TRC |
Ptriple | 1.9226×10-7 | atm | N/A | Goodwin and Haynes, 1982 | Uncertainty assigned by TRC = 5.×10-10 atm; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 407.7 ± 0.8 | K | AVG | N/A | Average of 10 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 36.0 ± 0.5 | atm | AVG | N/A | Average of 9 values; Individual data points |
Quantity | Value | Units | Method | Reference | Comment |
Vc | 0.259 | l/mol | N/A | Daubert, 1996 | |
Vc | 0.2591 | l/mol | N/A | Younglove and Ely, 1987 | Uncertainty assigned by TRC = 0.001 l/mol; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 3.85 ± 0.05 | mol/l | N/A | Daubert, 1996 | |
ρc | 3.880 | mol/l | N/A | Levelt Sengers, Kamgar-Parsi, et al., 1983 | Uncertainty assigned by TRC = 0.009 mol/l; TRC |
ρc | 3.91 | mol/l | N/A | Waxman and Gallagher, 1983 | Uncertainty assigned by TRC = 0.09 mol/l; TRC |
ρc | 3.8601 | mol/l | N/A | Goodwin and Haynes, 1982 | Uncertainty assigned by TRC = 0.03 mol/l; TRC |
ρc | 3.802 | mol/l | N/A | Beattie, Edwards, et al., 1949 | Uncertainty assigned by TRC = 0.1 mol/l; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ΔvapH° | 4.778 | kcal/mol | N/A | Majer and Svoboda, 1985 |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
5.0901 | 261.44 | N/A | Aston, Kennedy, et al., 1940, 2 | P = 101.325 kPa; DH |
5.09 | 261.3 | N/A | Majer and Svoboda, 1985 | |
5.14 | 318. | N/A | Lim, Park, et al., 1999 | Based on data from 303. to 333. K.; AC |
5.35 | 265. | A | Stephenson and Malanowski, 1987 | Based on data from 186. to 280. K.; AC |
6.43 | 172. | A | Stephenson and Malanowski, 1987 | Based on data from 121. to 187. K.; AC |
5.23 | 278. | A | Stephenson and Malanowski, 1987 | Based on data from 263. to 306. K.; AC |
5.11 | 316. | A | Stephenson and Malanowski, 1987 | Based on data from 301. to 366. K.; AC |
5.16 | 376. | A | Stephenson and Malanowski, 1987 | Based on data from 361. to 408. K.; AC |
5.16 | 292. | N/A | Steele, Poling, et al., 1976 | Based on data from 277. to 344. K. See also Boublik, Fried, et al., 1984.; AC |
5.09 | 286. | N/A | Reid, 1972 | AC |
5.1 ± 0.8 | 261.44 | V | Aston, Kennedy, et al., 1940, 3 | ALS |
5.40 | 247. | N/A | Aston, Kennedy, et al., 1940, 2 | Based on data from 188. to 262. K. See also Boublik, Fried, et al., 1984.; AC |
Entropy of vaporization
ΔvapS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
19.47 | 261.44 | Aston, Kennedy, et al., 1940, 2 | P; DH |
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 | Comment |
---|---|---|---|---|---|
261.31 to 408.12 | 4.3224 | 1132.108 | 0.918 | Das, Reed, et al., 1973 | Coefficents calculated by NIST from author's data. |
188.06 to 261.54 | 3.93846 | 912.141 | -29.808 | Aston, Kennedy, et al., 1940, 2 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.085 | 113.74 | Aston, Kennedy, et al., 1940, 2 | DH |
1.07 | 113.7 | Perkins and Magee, 2009 | AC |
1.09 | 113.7 | Domalski and Hearing, 1996 | AC |
1.075 | 113.2 | Parks, Shomate, et al., 1937, 2 | DH |
Entropy of fusion
ΔfusS (cal/mol*K) | Temperature (K) | Reference | Comment |
---|---|---|---|
9.541 | 113.74 | Aston, Kennedy, et al., 1940, 2 | DH |
9.496 | 113.2 | Parks, Shomate, et al., 1937, 2 | DH |
References
Go To: Top, Phase change data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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
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
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]
Aston, Kennedy, et al., 1940, 2
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]
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]
Parks, Shomate, et al., 1937, 2
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]
Notes
Go To: Top, Phase change data, References
- Symbols used in this document:
Pc Critical pressure Ptriple Triple point pressure Tboil Boiling point Tc Critical temperature Tfus Fusion (melting) point Ttriple Triple point temperature Vc Critical volume ΔfusH Enthalpy of fusion ΔfusS Entropy of fusion ΔvapH Enthalpy of vaporization ΔvapH° Enthalpy of vaporization at standard conditions ΔvapS Entropy of vaporization ρc Critical density - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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