Cyclohexane, ethyl-

Formula: C₈H₁₆
Molecular weight: 112.2126
IUPAC Standard InChI: InChI=1S/C8H16/c1-2-8-6-4-3-5-7-8/h8H,2-7H2,1H3
IUPAC Standard InChIKey: IIEWJVIFRVWJOD-UHFFFAOYSA-N
CAS Registry Number: 1678-91-7
Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
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Other names: Ethylcyclohexane
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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	-172.6	kJ/mol	N/A	Baroody and Carpenter, 1972	Value computed using Δ_fH_liquid° value of -213.0 kj/mol from Baroody and Carpenter, 1972 and Δ_vapH° value of 40.4 kj/mol from Prosen, Johnson, et al., 1946.; DRB
Δ_fH°_gas	-171.8 ± 1.5	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	ALS
Quantity	Value	Units	Method	Reference	Comment
S°_gas	382.67	J/mol*K	N/A	Huffman H.M., 1949	GT

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
40.95	50.	Thermodynamics Research Center, 1997	p=1 bar. There is an appreciable difference, mainly at high temperatures, with values estimated earlier by a method of increments [ Beckett C.W., 1947].; GT
62.69	100.
87.23	150.
111.7	200.
150.0	273.15
163.9	298.15
164.9	300.
219.6	400.
268.2	500.
308.9	600.
342.9	700.
371.6	800.
396.1	900.
416.9	1000.
434.8	1100.
450.2	1200.
463.4	1300.
474.9	1400.
484.8	1500.
504.2	1750.
518.2	2000.
528.6	2250.
536.3	2500.
542.3	2750.
547.0	3000.

Constant pressure heat capacity of gas

C_p,gas (J/mol*K)	Temperature (K)	Reference	Comment
152.23	298.15	Colgate S.O., 1990	These heat capacities determined from acoustical measurements are significantly lower than statistically calculated values [ Thermodynamics Research Center, 1997] (Cp(298.15 K)=163.9 J/molK) and values estimated by a method of increments [ Beckett C.W., 1947] (Cp(298.15 K)=158.6 J/molK). At the same time, the heat capacities of ethylbenzene determined in this work are only slightly below than calorimetric ones.; GT
170.36	323.15
197.90	373.15
217.63	408.15
239.88	448.15

Condensed phase thermochemistry data

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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
Δ_fH°_liquid	-213.	kJ/mol	Ccb	Baroody and Carpenter, 1972	ALS
Δ_fH°_liquid	-212.2 ± 1.5	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	ALS
Quantity	Value	Units	Method	Reference	Comment
Δ_cH°_liquid	-5222.6 ± 1.5	kJ/mol	Ccb	Prosen, Johnson, et al., 1946	Corresponding Δ_fHº_liquid = -212.1 kJ/mol (simple calculation by NIST; no Washburn corrections); ALS
Quantity	Value	Units	Method	Reference	Comment
S°_liquid	280.91	J/mol*K	N/A	Huffman, Todd, et al., 1949	DH
S°_liquid	281.6	J/mol*K	N/A	Parks, Moore, et al., 1949	Extrapolation below 80 K, 57.74 J/mol*K.; DH

Constant pressure heat capacity of liquid

C_p,liquid (J/mol*K)	Temperature (K)	Reference	Comment
211.79	298.15	Huffman, Todd, et al., 1949	T = 12 to 310 K.; DH
214.2	298.15	Parks, Moore, et al., 1949	T = 80 to 300 K.; DH

Reaction thermochemistry data

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Data compiled by: 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

+ = Cyclohexane, ethyl-

By formula: C₈H₁₄ + H₂ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-110. ± 1.	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon
Δ_rH°	-110.1 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid
Δ_rH°	-110.1 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid

+ = Cyclohexane, ethyl-

By formula: H₂ + C₈H₁₄ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-104.9 ± 0.54	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid
Δ_rH°	-104.9 ± 0.54	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid

+ 4 = Cyclohexane, ethyl-

By formula: C₈H₈ + 4H₂ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-320.1 ± 1.0	kJ/mol	Chyd	Dolliver, Gresham, et al., 1937	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -324.2 ± 0.84 kJ/mol; At 355 °K

+ 3 = Cyclohexane, ethyl-

By formula: C₈H₁₀ + 3H₂ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-201.6 ± 0.42	kJ/mol	Chyd	Dolliver, Gresham, et al., 1937	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -204.7 ± 0.4 kJ/mol; At 355 °K

+ = Cyclohexane, ethyl-

By formula: H₂ + C₈H₁₄ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-117. ± 3.	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon

References

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

Baroody and Carpenter, 1972
Baroody, E.E.; Carpenter, G.A., Heats of formation of propellant compounds (U), Rpt. Naval Ordnance Systems Command Task No. 331-003/067-1/UR2402-001 for Naval Ordance Station, Indian Head, MD, 1972, 1-9. [all data]

Prosen, Johnson, et al., 1946
Prosen, E.J.; Johnson, W.H.; Rossini, F.D., Heats of formation and combustion of the normal alkylcyclopentanes and cyclohexanes and the increment per CH₂ group for several homologous series of hydrocarbons, J. Res. NBS, 1946, 37, 51-56. [all data]

Huffman H.M., 1949
Huffman H.M., Low-temperature thermal data on eight C8H16 alkylcyclohexanes, J. Am. Chem. Soc., 1949, 71, 584-592. [all data]

Thermodynamics Research Center, 1997
Thermodynamics Research Center, Selected Values of Properties of Chemical Compounds., Thermodynamics Research Center, Texas A&M University, College Station, Texas, 1997. [all data]

Beckett C.W., 1947
Beckett C.W., The thermodynamic properties and molecular structure of cyclohexane, methylcyclohexane, ethylcyclohexane, and seven dimethylcyclohexanes, J. Am. Chem. Soc., 1947, 69, 2488-2495. [all data]

Colgate S.O., 1990
Colgate S.O., Acoustical determination of ideal gas heat capacities of three C-8 compounds, Fluid Phase Equilib., 1990, 60, 191-203. [all data]

Huffman, Todd, et al., 1949
Huffman, H.M.; Todd, S.S.; Oliver, G.D., Low temperature thermal data on eight C₈H₁₆ alkylcyclohexanes, J. Am. Chem. Soc., 1949, 71, 584-592. [all data]

Parks, Moore, et al., 1949
Parks, G.S.; Moore, G.E.; Renquist, M.L.; Naylor, B.F.; McClaine, L.A.; Fujii, P.S.; Hatton, J.A., Thermal data on organic compounds. XXV. Some heat capacity, entropy and free energy data for nine hydrocarbons of high molecular weight, J. Am. Chem. Soc., 1949, 71, 3386-3389. [all data]

Rogers and McLafferty, 1971
Rogers, D.W.; McLafferty, F.J., A new hydrogen calorimeter. Heats of hydrogenation of allyl and vinyl unsaturation adjacent to a ring, Tetrahedron, 1971, 27, 3765-3775. [all data]

Turner and Garner, 1958
Turner, R.B.; Garner, R.H., Heats of hydrogenation. V. Relative stabilities in certain exocyclic-endocyclic olefin pairs, J. Am. Chem. Soc., 1958, 80, 1424-1430. [all data]

Turner and Garner, 1957
Turner, R.B.; Garner, R.H., Heats of hydrogenation. V. Relative stabilities in certain exocyclic-endocyclic olefin pairs, J. Am. Chem. Soc., 1957, 80, 1424-1430. [all data]

Dolliver, Gresham, et al., 1937
Dolliver, M.a.; Gresham, T.L.; Kistiakowsky, G.B.; Vaughan, W.E., Heats of organic reactions. V. Heats of hydrogenation of various hydrocarbons, J. Am. Chem. Soc., 1937, 59, 831-841. [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]

Notes

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Symbols used in this document:

C_p,gas	Constant pressure heat capacity of gas
C_p,liquid	Constant pressure heat capacity of liquid
S°_gas	Entropy of gas at standard conditions
S°_liquid	Entropy of liquid at standard conditions
Δ_cH°_liquid	Enthalpy of combustion of liquid at standard conditions
Δ_fH°_gas	Enthalpy of formation of gas at standard conditions
Δ_fH°_liquid	Enthalpy of formation of liquid at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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