Ethane

Formula: C₂H₆
Molecular weight: 30.0690
IUPAC Standard InChI: InChI=1S/C2H6/c1-2/h1-2H3
IUPAC Standard InChIKey: OTMSDBZUPAUEDD-UHFFFAOYSA-N
CAS Registry Number: 74-84-0
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.
Species with the same structure:
- 1-Ethenyl-1-methyl-2,4-bis-(1-methylethenyl)-1S-1α,2β,4α-cyclohexane
Isotopologues:
- pentadeuteroethane
- Ethane-d1
Other names: Bimethyl; Dimethyl; Ethyl hydride; Methylmethane; C2H6; UN 1035; UN 1961
Information on this page:
Other data available:
Data at other public NIST sites:
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Gas phase thermochemistry data

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Data compiled as indicated in comments:
DRB - Donald R. Burgess, Jr.
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
Δ_fH°_gas	-20. ± 0.1	kcal/mol	Review	Manion, 2002	adopted recommendation of Gurvich, Veyts, et al., 1991; DRB
Δ_fH°_gas	-20.04 ± 0.07	kcal/mol	Ccb	Pittam and Pilcher, 1972	ALS
Δ_fH°_gas	-20.24 ± 0.12	kcal/mol	Ccb	Prosen and Rossini, 1945	Hf derived from Heat of Hydrogenation; ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_gas	-373.01 ± 0.06	kcal/mol	Ccb	Pittam and Pilcher, 1972	Corresponding Δ_fHº_gas = -20.04 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_gas	-372.82 ± 0.11	kcal/mol	Ccb	Prosen and Rossini, 1945	Hf derived from Heat of Hydrogenation; Corresponding Δ_fHº_gas = -20.23 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS
Δ_cH°_gas	-372.81 ± 0.11	kcal/mol	Ccb	Rossini, 1934	Corresponding Δ_fHº_gas = -20.24 kcal/mol (simple calculation by NIST; no Washburn corrections); ALS

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
8.533	100.	Gurvich, Veyts, et al., 1989	p=1 bar. Recommended entropies and heat capacities are in good agreement with those obtained from other statistical thermodynamic calculations [ Pitzer K.S., 1944, Chao J., 1973, Pamidimukkala K.M., 1982].; GT
10.11	200.
12.55	298.15
12.60	300.
15.65	400.
18.63	500.
21.32	600.
23.70	700.
25.798	800.
27.655	900.
29.290	1000.
30.724	1100.
31.979	1200.
33.076	1300.
34.034	1400.
34.871	1500.
35.607	1600.
36.250	1700.
36.816	1800.
37.318	1900.
37.763	2000.
38.157	2100.
38.509	2200.
38.822	2300.
39.104	2400.
39.357	2500.
39.587	2600.
39.792	2700.
39.981	2800.
40.153	2900.
40.308	3000.

Constant pressure heat capacity of gas

C_p,gas (cal/mol*K)	Temperature (K)	Reference	Comment
9.957 ± 0.074	189.20	Halford J.O., 1957	Please also see Eucken A., 1933, Kistiakowsky G.B., 1939, Dailey B.P., 1943.; GT
10.34 ± 0.076	209.30
10.77 ± 0.081	229.65
11.30 ± 0.084	249.90
11.27 ± 0.084	250.15
11.87 ± 0.088	272.00
11.83 ± 0.01	272.07
12.11 ± 0.10	279.00
12.46 ± 0.093	292.00
12.73 ± 0.02	302.70
13.72 ± 0.01	335.82
14.08	347.65
14.43	359.75
14.59 ± 0.024	364.78
14.84 ± 0.11	373.60
15.27	387.55
17.31	451.95
19.14	520.55
20.62	561.65
21.62	603.25

Condensed phase thermochemistry data

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Data compiled by: Eugene S. Domalski and Elizabeth D. Hearing

Quantity	Value	Units	Method	Reference	Comment
S°_liquid	30.28	cal/mol*K	N/A	Witt and Kemp, 1937	Entropy from 0 to 15 K calculated using a Debye function.

Constant pressure heat capacity of liquid

C_p,liquid (cal/mol*K)	Temperature (K)	Reference	Comment
16.41	100.	Atake and Chihara, 1976	T = 50 to 100 K. Data given graphically. Cp = 0.69933 (T/K) - 2.385 J/mol*K (50 to 70 K, for solid).
16.4	94.	Roder, 1976	From data 90.3 to 94 K. Average value over range.
16.36	100.32	Roder, 1976, 2	T = 93 to 301 K (saturation line), 91 to 330 K, pressures from 0 to 33 MPa.
17.26	180.	Witt and Kemp, 1937	T = 15 to 185 K.
17.80	200.	Wiebe, Hubbard, et al., 1930	T = 67 to 305.2 K. Heat capacity of saturated liquid given to 295 K is 136.1 J/mol*K.

Phase change data

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, References, Notes

Data compiled as indicated in comments:
DH - Eugene S. Domalski and Elizabeth D. Hearing
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos

Quantity	Value	Units	Method	Reference	Comment
T_boil	184.6 ± 0.6	K	AVG	N/A	Average of 23 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
T_fus	101.	K	N/A	Streng, 1971	Uncertainty assigned by TRC = 1. K; TRC
T_fus	89.2	K	N/A	Timmermans, 1935	Uncertainty assigned by TRC = 1.5 K; TRC
Quantity	Value	Units	Method	Reference	Comment
T_triple	91. ± 6.	K	AVG	N/A	Average of 10 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
P_triple	0.000011	atm	N/A	Younglove and Ely, 1987	Uncertainty assigned by TRC = 5.×10^-9 atm; TRC
Quantity	Value	Units	Method	Reference	Comment
T_c	305.3 ± 0.3	K	AVG	N/A	Average of 41 out of 46 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
P_c	49. ± 1.	atm	AVG	N/A	Average of 28 out of 29 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
V_c	0.147 ± 0.002	l/mol	AVG	N/A	Average of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
ρ_c	6.9 ± 0.4	mol/l	AVG	N/A	Average of 19 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_vapH°	2.33	kcal/mol	N/A	Majer and Svoboda, 1985

Enthalpy of vaporization

Δ_vapH (kcal/mol)	Temperature (K)	Method	Reference	Comment
3.5141	184.1	N/A	Witt and Kemp, 1937	DH
3.66	288.	A	Stephenson and Malanowski, 1987	Based on data from 273. to 305. K.; AC
3.75	170.	A	Stephenson and Malanowski, 1987	Based on data from 154. to 185. K.; AC
4.23	114.	A	Stephenson and Malanowski, 1987	Based on data from 95. to 129. K.; AC
3.56	214.	A	Stephenson and Malanowski, 1987	Based on data from 185. to 229. K.; AC
3.56	259.	A	Stephenson and Malanowski, 1987	Based on data from 228. to 274. K.; AC
4.09	129.	N/A	Carruth and Kobayashi, 1973	Based on data from 91. to 144. K.; AC
3.51	210.	N/A	Reid, 1972	AC
3.51	184.	N/A	Witt and Kemp, 1937	AC
3.66	185.	N/A	Loomis and Walters, 1926	Based on data from 136. to 200. K.; AC

Enthalpy of vaporization

Δ_vapH = A exp(-βT_r) (1 − T_r)^β
Δ_vapH = Enthalpy of vaporization (at saturation pressure) (kcal/mol)
T_r = reduced temperature (T / T_c)

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Temperature (K)	A (kcal/mol)	β	T_c (K)	Reference
289. to 301.	7.034	0.3696	305.4	Majer and Svoboda, 1985

Entropy of vaporization

Δ_vapS (cal/mol*K)	Temperature (K)	Reference	Comment
19.09	184.1	Witt and Kemp, 1937	DH

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
91.33 to 144.13	4.50135	791.3	-6.422	Carruth and Kobayashi, 1973	Coefficents calculated by NIST from author's data.
135.74 to 199.91	3.93264	659.739	-16.719	Loomis and Walters, 1926	Coefficents calculated by NIST from author's data.

Enthalpy of sublimation

Δ_subH (kcal/mol)	Temperature (K)	Method	Reference	Comment
5.40	85.	N/A	Regnier, 1972	Based on data from 80. to 90. K.; AC
4.90	90.	B	Bondi, 1963	AC

Enthalpy of fusion

Δ_fusH (kcal/mol)	Temperature (K)	Reference	Comment
0.139	90.341	Atake and Chihara, 1976	Triple point.; DH
0.667	89.5	Domalski and Hearing, 1996	AC
0.14	90.3	Atake and Chihara, 1976	AC

Entropy of fusion

Δ_fusS (cal/mol*K)	Temperature (K)	Reference	Comment
1.54	90.341	Atake and Chihara, 1976	Triple; DH

Enthalpy of phase transition

ΔH_trs (kcal/mol)	Temperature (K)	Initial Phase	Final Phase	Reference	Comment
0.5454	89.813	crystaline, II	crystaline, I	Atake and Chihara, 1976	DH
0.6828	89.87	crystaline, I	liquid	Witt and Kemp, 1937	DH
0.6675	89.50	crystaline, I	liquid	Wiebe, Hubbard, et al., 1930	DH
0.58258	89.77	crystaline, II	crystaline, I	Roder, 1976	DH

Entropy of phase transition

ΔS_trs (cal/mol*K)	Temperature (K)	Initial Phase	Final Phase	Reference	Comment
6.090	89.813	crystaline, II	crystaline, I	Atake and Chihara, 1976	DH
7.60	89.87	crystaline, I	liquid	Witt and Kemp, 1937	DH
7.46	89.50	crystaline, I	liquid	Wiebe, Hubbard, et al., 1930	DH
6.489	89.77	crystaline, II	crystaline, I	Roder, 1976	DH

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

Manion, 2002
Manion, J.A., Evaluated Enthalpies of Formation of the Stable Closed Shell C1 and C2 Chlorinated Hydrocarbons, J. Phys. Chem. Ref. Data, 2002, 31, 1, 123-172, https://doi.org/10.1063/1.1420703 . [all data]

Gurvich, Veyts, et al., 1991
Thermodynamic Properties of Individual Substances, 4th edition, Volume 2, Gurvich, L.V.; Veyts, I.V.; Alcock, C.B.;, ed(s)., Hemisphere, New York, 1991. [all data]

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 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]

Rossini, 1934
Rossini, F.D., Calorimetric determination of the heats of combustion of ethane, propane, normal butane, and normal pentane, J. Res. NBS, 1934, 12, 735-750. [all data]

Gurvich, Veyts, et al., 1989
Gurvich, L.V.; Veyts, I.V.; Alcock, C.B., Thermodynamic Properties of Individual Substances, 4th ed.; Vols. 1 and 2, Hemisphere, New York, 1989. [all data]

Pitzer K.S., 1944
Pitzer K.S., Thermodynamics of gaseous paraffins. Specific heat and related properties, Ind. Eng. Chem., 1944, 36, 829-831. [all data]

Chao J., 1973
Chao J., Ideal gas thermodynamic properties of ethane and propane, J. Phys. Chem. Ref. Data, 1973, 2, 427-438. [all data]

Pamidimukkala K.M., 1982
Pamidimukkala K.M., Ideal gas thermodynamic properties of CH3, CD3, CD4, C2D2, C2D4, C2D6, C2H6, CH3N2CH3, and CD3N2CD3, J. Phys. Chem. Ref. Data, 1982, 11, 83-99. [all data]

Halford J.O., 1957
Halford J.O., Standard heat capacities of gaseous methanol, ethanol, methane and ethane at 279 K by thermal conductivity, J. Phys. Chem., 1957, 61, 1536-1539. [all data]

Eucken A., 1933
Eucken A., Molar heats and normal frequencies of ethane and ethylene, Z. Phys. Chem., 1933, B20, 184-194. [all data]

Kistiakowsky G.B., 1939
Kistiakowsky G.B., Gaseous heat capacities. I. The method and the heat capacities of C2H6 and C2D6, J. Chem. Phys., 1939, 7, 281-288. [all data]

Dailey B.P., 1943
Dailey B.P., The heat capacities at higher temperatures of ethane and propane, J. Am. Chem. Soc., 1943, 65, 42-44. [all data]

Witt and Kemp, 1937
Witt, R.K.; Kemp, J.D., The heat capacity of ethane from 15°K to the boiling point. The heat of fusion and the heat of vaporization, J. Am. Chem. Soc., 1937, 59, 273-276. [all data]

Atake and Chihara, 1976
Atake, T.; Chihara, H., Calorimetric study of the phase changes in solid ethane, Chem. Lett., 1976, (7), 683-688. [all data]

Roder, 1976
Roder, H.M., The heats of transition of solid ethane, J. Chem. Phys., 1976, 65, 1371-1373. [all data]

Roder, 1976, 2
Roder, H.M., Measurements of the specific heats, Ca, and Cv, of dense gaseous and liquid ethane, J. Res., 1976, NBS 80A, 739-759. [all data]

Wiebe, Hubbard, et al., 1930
Wiebe, R.; Hubbard, K.H.; Brevoort, M.J., The heat capacity of saturated liquid ethane from the boiling point to the critical temperature and heat fusion of the solid, J. Am. Chem. Soc., 1930, 52, 611-622. [all data]

Streng, 1971
Streng, A.G., Miscibility and Compatibility of Some Liquid and Solidified Gases at Low Temperature, J. Chem. Eng. Data, 1971, 16, 357. [all data]

Timmermans, 1935
Timmermans, J., Researches in Stoichiometry. I. The Heat of Fusion of Organic Compounds., Bull. Soc. Chim. Belg., 1935, 44, 17-40. [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]

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]

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]

Carruth and Kobayashi, 1973
Carruth, Grant F.; Kobayashi, Riki, Vapor pressure of normal paraffins ethane through n-decane from their triple points to about 10 mm mercury, J. Chem. Eng. Data, 1973, 18, 2, 115-126, https://doi.org/10.1021/je60057a009 . [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]

Loomis and Walters, 1926
Loomis, A.G.; Walters, J.E., THE VAPOR PRESSURE OF ETHANE NEAR THE NORMAL BOILING POINT ¹, J. Am. Chem. Soc., 1926, 48, 8, 2051-2055, https://doi.org/10.1021/ja01419a006 . [all data]

Regnier, 1972
Regnier, J., J. Chim. Phys. Phys.-Chim. Biol., 1972, 69, 6, 942. [all data]

Bondi, 1963
Bondi, A., Heat of Siblimation of Molecular Crystals: A Catalog of Molecular Structure Increments., J. Chem. Eng. Data, 1963, 8, 3, 371-381, https://doi.org/10.1021/je60018a027 . [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]

Notes

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

Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
P_c	Critical pressure
P_triple	Triple point pressure
S°_liquid	Entropy of liquid at standard conditions
T_boil	Boiling point
T_c	Critical temperature
T_fus	Fusion (melting) point
T_triple	Triple point temperature
V_c	Critical volume
ΔH_trs	Enthalpy of phase transition
ΔS_trs	Entropy of phase transition
Δ_cH°_gas	Enthalpy of combustion of gas at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fusH	Enthalpy of fusion
Δ_fusS	Entropy of fusion
Δ_subH	Enthalpy of sublimation
Δ_vapH	Enthalpy of vaporization
Δ_vapH°	Enthalpy of vaporization at standard conditions
Δ_vapS	Entropy of vaporization
ρ_c	Critical density

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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