Hydrogen

Formula: H₂
Molecular weight: 2.01588
IUPAC Standard InChI: InChI=1S/H2/h1H
IUPAC Standard InChIKey: UFHFLCQGNIYNRP-UHFFFAOYSA-N
CAS Registry Number: 1333-74-0
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.
Isotopologues:
Other names: Dihydrogen; o-Hydrogen; p-Hydrogen; Molecular hydrogen; H2; UN 1049; UN 1966
Permanent link for this species. Use this link for bookmarking this species for future reference.
Information on this page:
Other data available:
Data at other public NIST sites:
- Electron-Impact Ionization Cross Sections (on physics web site)
- Gas Phase Kinetics Database
Options:
- Switch to calorie-based units

Data at NIST subscription sites:

NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.

Gas phase thermochemistry data

Go To: Top, Phase change data, Reaction thermochemistry data, References, Notes

Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	130.680 ± 0.003	J/mol*K	Review	Cox, Wagman, et al., 1984	CODATA Review value
S°_{gas,1 bar}	130.68	J/mol*K	Review	Chase, 1998	Data last reviewed in March, 1977

Gas Phase Heat Capacity (Shomate Equation)

C_p° = A + B*t + C*t² + D*t³ + E/t²
H° − H°_298.15= A*t + B*t²/2 + C*t³/3 + D*t⁴/4 − E/t + F − H
S° = A*ln(t) + B*t + C*t²/2 + D*t³/3 − E/(2*t²) + G
C_p = heat capacity (J/mol*K)
H° = standard enthalpy (kJ/mol)
S° = standard entropy (J/mol*K)
t = temperature (K) / 1000.

View plot Requires a JavaScript / HTML 5 canvas capable browser.

View table.

Temperature (K)	298. to 1000.	1000. to 2500.	2500. to 6000.
A	33.066178	18.563083	43.413560
B	-11.363417	12.257357	-4.293079
C	11.432816	-2.859786	1.272428
D	-2.772874	0.268238	-0.096876
E	-0.158558	1.977990	-20.533862
F	-9.980797	-1.147438	-38.515158
G	172.707974	156.288133	162.081354
H	0.0	0.0	0.0
Reference	Chase, 1998	Chase, 1998	Chase, 1998
Comment	Data last reviewed in March, 1977; New parameter fit October 2001	Data last reviewed in March, 1977; New parameter fit October 2001	Data last reviewed in March, 1977; New parameter fit October 2001

Phase change data

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

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director

Quantity	Value	Units	Method	Reference	Comment
T_triple	0.	K	N/A	Roder, Childs, et al., 1973	TRC
T_triple	13.95	K	N/A	Clusius and Weigand, 1940	Uncertainty assigned by TRC = 0.06 K; see property X for dP/dT for c-l equil.; TRC
T_triple	13.96	K	N/A	Henning and Otto, 1936	Uncertainty assigned by TRC = 0.05 K; temperature measured with He gas thermometer; TRC
Quantity	Value	Units	Method	Reference	Comment
P_triple	0.	bar	N/A	Roder, Childs, et al., 1973	TRC
P_triple	0.0721	bar	N/A	Henning and Otto, 1936	Uncertainty assigned by TRC = 0.0004 bar; TRC
Quantity	Value	Units	Method	Reference	Comment
T_c	33.18	K	N/A	Onnes, Crommelin, et al., 1917	Uncertainty assigned by TRC = 0.2 K; derived from P-V-T measurements; TRC
Quantity	Value	Units	Method	Reference	Comment
P_c	13.00	bar	N/A	Onnes, Crommelin, et al., 1917	Uncertainty assigned by TRC = 0.0119 bar; derived from vapor pressure extrapolated to Tc; TRC
Quantity	Value	Units	Method	Reference	Comment
ρ_c	15.4	mol/l	N/A	Onnes, Crommelin, et al., 1917	Uncertainty assigned by TRC = 2. mol/l; by extrapolation of rectilinear diameter to Tc; TRC

Antoine Equation Parameters

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

View plot Requires a JavaScript / HTML 5 canvas capable browser.

Temperature (K)	A	B	C	Reference	Comment
21.01 to 32.27	3.54314	99.395	7.726	van Itterbeek, Verbeke, et al., 1964	Coefficents calculated by NIST from author's data.

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, Phase change data, References, Notes

Data compiled as indicated in comments:
MS - José A. Martinho Simões
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
B - John E. Bartmess

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.

Reactions 1 to 50

(solution) + Hydrogen (solution) = 2 (solution)

By formula: C₈Co₂O₈ (solution) + H₂ (solution) = 2C₄HCoO₄ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	19.7 ± 0.8	kJ/mol	EqS	Rathke, Klingler, et al., 1992	solvent: Supercritical carbon dioxide; Temperature range: 333-453 K. The results corrected for 1 atm pressure of H2 are 16.7 kJ/mol and -17.6 J/(mol K) Rathke, Klingler, et al., 1992; MS
Δ_rH°	13.0 ± 0.9	kJ/mol	EqS	Bor, 1986	solvent: n-Hexane; Temperature range: ca. 300-420 K; MS
Δ_rH°	26.4	kJ/mol	KinS	Alemdaroglu, Penninger, et al., 1976	solvent: n-Heptane; The reaction enthalpy relies on the experimental values for the forward and reverse activation enthalpies, 72.4 and 46.0 kJ/mol, respectively Alemdaroglu, Penninger, et al., 1976. A rather different value has, however, been reported for the activation enthalpy of the forward reaction, 104.6 kJ/mol Ungváry, 1972; MS
Δ_rH°	27.6	kJ/mol	EqS	Alemdaroglu, Penninger, et al., 1976	solvent: n-Heptane; Temperature range: 353-428 K; MS
Δ_rH°	13.4	kJ/mol	EqS	Ungváry, 1972	solvent: n-Heptane; Temperature range: 307-428 K. The results corrected for 1 atm pressure of H2 are 18.0 kJ/mol and -10.9 J/(mol K) Rathke, Klingler, et al., 1992; MS

H₃⁺ + Hydrogen = (H₃⁺ • )

By formula: H₃⁺ + H₂ = (H₃⁺ • H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	29. ± 2.	kJ/mol	AVG	N/A	Average of 4 out of 11 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8 to 72.8	J/mol*K	RNG	N/A	Range of 6 values; Individual data points

C₁₁H₂O₁₁Os (solution) + (solution) = Hydrogen (g) + (solution)

By formula: C₁₁H₂O₁₁Os (solution) + CO (solution) = H₂ (g) + C₁₂O₁₂Os₃ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-37.7 ± 9.6	kJ/mol	ES/KS	Poë, Sampson, et al., 1993	solvent: Decalin; Calculated from equilibrium and kinetic data Poë, Sampson, et al., 1993.; MS
Δ_rH°	-77.4 ± 9.7	kJ/mol	N/A	Poë, Sampson, et al., 1993	solvent: Decalin; Calculated from data for the reactions Os3(CO)10(H)2(solution) + CO(solution) = Os3(CO)11(H)2(solution) (hrxn [kJ/mol]=-39.7±1.3, srxn [J/(mol K)]=-80.3±3.8) and Os3(CO)11(H)2(solution) + CO(solution) = Os3(CO)12(solution) + H2(g) (hrxn [kJ/mol]=-37.7±9.6, srxn [J/(mol K)]=-32.6±27.6) Poë, Sampson, et al., 1993.; MS

+ Hydrogen =

By formula: C₆H₁₀ + H₂ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-118. ± 6.	kJ/mol	AVG	N/A	Average of 8 values; Individual data points

(cr) + Hydrogen (g) = 2C₈H₆CrO₃ (cr)

By formula: C₁₆H₁₀Cr₂O₆ (cr) + H₂ (g) = 2C₈H₆CrO₃ (cr)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-13.9 ± 4.0	kJ/mol	RSC	Landrum and Hoff, 1985	The reaction enthalpy was obtained from the value for the reaction 2Cr(Cp)(CO)3(H)(cr) + 1,3-cy-C6H8(solution) = [Cr(Cp)(CO)3]2(cr) + cy-C6H10(solution), -98.3 ± 3.8 kJ/mol Landrum and Hoff, 1985, together with the calculated enthalpy for 1,3-cy-C6H8(l) + H2(g) = cy-C6H10(l), -112.2±1.3 Pedley, 1994. It was assumed that 1,3-cy-C6H8 and cy-C6H10 have similar solution enthalpies in heptane; MS
Δ_rH°	-15.1 ± 4.2	kJ/mol	DSC	Landrum and Hoff, 1985	The reaction enthalpy was obtained from the value for the reaction 2Cr(Cp)(CO)3(H)(cr) + 1,3-cy-C6H8(solution) = [Cr(Cp)(CO)3]2(cr) + cy-C6H10(solution), -98.3 ± 3.8 kJ/mol Landrum and Hoff, 1985, together with the calculated enthalpy for 1,3-cy-C6H8(l) + H2(g) = cy-C6H10(l), -112.2±1.3 Pedley, 1994. It was assumed that 1,3-cy-C6H8 and cy-C6H10 have similar solution enthalpies in heptane; MS

Hydrogen + =

By formula: H₂ + C₆H₁₂ = C₆H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-125. ± 3.	kJ/mol	AVG	N/A	Average of 8 values; Individual data points

(H₃⁺ • Hydrogen ) + = (H₃⁺ • 2)

By formula: (H₃⁺ • H₂) + H₂ = (H₃⁺ • 2H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	14. ± 0.8	kJ/mol	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rH°	13.	kJ/mol	HPMS	Beuhler, Ehrenson, et al., 1983	gas phase; M
Δ_rH°	14.	kJ/mol	HPMS	Beuhler, Ehrenson, et al., 1983	gas phase; deuterated; M
Δ_rH°	17.	kJ/mol	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M
Δ_rH°	7.5	kJ/mol	HPMS	Bennett and Field, 1972	gas phase; Entropy change is questionable; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	72.8	J/mol*K	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rS°	70.7	J/mol*K	HPMS	Beuhler, Ehrenson, et al., 1983	gas phase; M
Δ_rS°	67.4	J/mol*K	HPMS	Beuhler, Ehrenson, et al., 1983	gas phase; deuterated; M
Δ_rS°	82.8	J/mol*K	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M
Δ_rS°	45.2	J/mol*K	HPMS	Bennett and Field, 1972	gas phase; Entropy change is questionable; M

Hydrogen + =

By formula: H₂ + C₇H₁₄ = C₇H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-125. ± 2.	kJ/mol	AVG	N/A	Average of 6 values; Individual data points

+ Hydrogen =

By formula: C₈H₁₆ + H₂ = C₈H₁₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-125. ± 6.	kJ/mol	AVG	N/A	Average of 7 values; Individual data points

+ = Hydrogen

By formula: H^- + H⁺ = H₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	1675.3	kJ/mol	N/A	Shiell, Hu, et al., 2000	gas phase; Given: 139714.8±1 cm-1 at 0K, or 399.465±0.003 kcal/mol; B
Δ_rH°	1675.3	kJ/mol	N/A	Pratt, McCormack, et al., 1992	gas phase; 399.46±0.01 kcal/mol at 0K; 0.94 correction, Gurvich, Veyts, et al.; B
Δ_rH°	1675.3	kJ/mol	D-EA	Lykke, Murray, et al., 1991	gas phase; Reported: 6082.99±0.15 cm-1, or 0.754195(18) eV; B
Quantity	Value	Units	Method	Reference	Comment
Δ_rG°	1649.3 ± 0.42	kJ/mol	H-TS	Shiell, Hu, et al., 2000	gas phase; Given: 139714.8±1 cm-1 at 0K, or 399.465±0.003 kcal/mol; B
Δ_rG°	1649.3	kJ/mol	H-TS	Lykke, Murray, et al., 1991	gas phase; Reported: 6082.99±0.15 cm-1, or 0.754195(18) eV; B

Hydrogen + =

By formula: H₂ + C₅H₈ = C₅H₁₀

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-112.7 ± 0.54	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane; ALS
Δ_rH°	-112. ± 0.8	kJ/mol	Chyd	Roth and Lennartz, 1980	liquid phase; solvent: Cyclohexane; ALS
Δ_rH°	-109.0 ± 1.8	kJ/mol	Chyd	Turner, Jarrett, et al., 1973	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-110. ± 0.8	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon; ALS
Δ_rH°	-111.6 ± 0.3	kJ/mol	Chyd	Dolliver, Gresham, et al., 1937	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -112.6 ± 0.3 kJ/mol; At 355 °K; ALS

Hydrogen + =

By formula: H₂ + C₈H₁₄ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-102.	kJ/mol	Chyd	Doering, Roth, et al., 1989	liquid phase; ALS
Δ_rH°	-103. ± 0.8	kJ/mol	Chyd	Roth and Lennartz, 1980	liquid phase; solvent: Cyclohexane; ALS
Δ_rH°	-96.40 ± 0.71	kJ/mol	Chyd	Rogers, Von Voithenberg, et al., 1978	liquid phase; solvent: Hexane; ALS
Δ_rH°	-96.1 ± 0.4	kJ/mol	Chyd	Turner and Meador, 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-97.40 ± 0.63	kJ/mol	Chyd	Conn, Kistiakowsky, et al., 1939	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -98.4 ± 0.2 kJ/mol; At 355 K; ALS

0.5C₃₆H₈₄Cl₂P₄Rh₂ (solution) + Hydrogen (g) = C₁₈H₄₄ClP₂Rh (solution)

By formula: 0.5C₃₆H₈₄Cl₂P₄Rh₂ (solution) + H₂ (g) = C₁₈H₄₄ClP₂Rh (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-98.8 ± 2.7	kJ/mol	RSC	Wang, Rosini, et al., 1995	solvent: Benzene; The reaction enthalpy was calculated from the enthalpies of the reactions Rh[P(i-Pr)3]2(Cl)(H)2(solution) + t-BuNC(solution) = Rh[P(i-Pr)3]2(Cl)(CN-t-Bu)(solution) + H2(g), -41.4 ± 1.7 kJ/mol, and 0.5{Rh[P(i-Pr)3]2(Cl)}2(solution) + t-BuNC(solution) = Rh[P(i-Pr)3]2(Cl)(CN-t-Bu)(solution), -140.2 ± 2.1 kJ/mol Wang, Rosini, et al., 1995. The enthalpy of solution of {Rh[P(i-Pr)3]2(Cl)}2(cr) was measured as 20.1 ± 1.3 kJ/mol Wang, Rosini, et al., 1995.; MS

Hydrogen + =

By formula: H₂ + C₆H₁₀ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-100.8 ± 0.63	kJ/mol	Chyd	Rogers, Crooks, et al., 1987	liquid phase; ALS
Δ_rH°	-101.3 ± 0.50	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane; ALS
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-96.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957, 2	liquid phase; solvent: Acetic acid; ALS

2 Hydrogen + =

By formula: 2H₂ + C₆H₁₀ = C₆H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-252. ± 2.	kJ/mol	Chyd	Fang and Rogers, 1992	liquid phase; solvent: Cyclohexane; ALS
Δ_rH°	-253.9 ± 2.7	kJ/mol	Chyd	Molnar, Rachford, et al., 1984	liquid phase; solvent: Dioxane; ALS
Δ_rH°	-251.8 ± 1.5	kJ/mol	Chyd	Turner, Mallon, et al., 1973	liquid phase; solvent: Glacial acetic acid; ALS
Δ_rH°	-251.2 ± 0.42	kJ/mol	Chyd	Kistiakowsky, Ruhoff, et al., 1936	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -253.3 ± 0.63 kJ/mol; At 355 °K; ALS

Hydrogen + =

By formula: H₂ + C₇H₁₂ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-101.9 ± 0.63	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane; ALS
Δ_rH°	-98.3 ± 0.8	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon; ALS
Δ_rH°	-98.58 ± 0.46	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-98.58 ± 0.46	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS

Hydrogen + =

By formula: H₂ + C₇H₁₂ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-106.9 ± 0.4	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane; ALS
Δ_rH°	-101. ± 0.8	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon; ALS
Δ_rH°	-104.1 ± 0.50	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-104.1 ± 0.50	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS

Hydrogen + =

By formula: H₂ + C₆H₁₀ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-115.9 ± 0.96	kJ/mol	Chyd	Allinger, Dodziuk, et al., 1982	liquid phase; solvent: Hexane; ALS
Δ_rH°	-112.5 ± 0.08	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-112.3 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-112.2 ± 0.3	kJ/mol	Chyd	Turner and Garner, 1957, 2	liquid phase; solvent: Acetic acid; ALS

C₃H₇⁺ + Hydrogen = (C₃H₇⁺ • )

By formula: C₃H₇⁺ + H₂ = (C₃H₇⁺ • H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	10.	kJ/mol	PHPMS	Hiraoka and Kebarle, 1976	gas phase; Entropy change calculated or estimated, DG<, Δ_rH<; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	84.	J/mol*K	N/A	Hiraoka and Kebarle, 1976	gas phase; Entropy change calculated or estimated, DG<, Δ_rH<; M

Free energy of reaction

Δ_rG° (kJ/mol)	T (K)	Method	Reference	Comment
4.	170.	PHPMS	Hiraoka and Kebarle, 1976	gas phase; Entropy change calculated or estimated, DG<, Δ_rH<; M

+ Hydrogen = ( • )

By formula: Co⁺ + H₂ = (Co⁺ • H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	82. ± 4.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(O K)=76.1 kJ/mol, Δ_rS(300 K)=86.2 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	92.0	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(O K)=76.1 kJ/mol, Δ_rS(300 K)=86.2 J/mol*K; M

Enthalpy of reaction

Δ_rH° (kJ/mol)	T (K)	Method	Reference	Comment
73.2 (+9.6,-0.)		CID	Haynes and Armentrout, 1996	gas phase; guided ion beam CID; M

+ Hydrogen =

By formula: C₅H₁₀ + H₂ = C₅H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-126.6 ± 2.4	kJ/mol	Chyd	Molnar, Rachford, et al., 1984	liquid phase; solvent: Dioxane; ALS
Δ_rH°	-125.0 ± 1.8	kJ/mol	Chyd	Molnar, Rachford, et al., 1984	liquid phase; solvent: Hexane; ALS
Δ_rH°	-122.6 ± 2.4	kJ/mol	Chyd	Rogers and Skanupong, 1974	liquid phase; solvent: Hexane; ALS
Δ_rH°	-119. ± 1.	kJ/mol	Chyd	Rogers and McLafferty, 1971	liquid phase; solvent: Hydrocarbon; ALS

+ Hydrogen =

By formula: C₇H₁₂ + H₂ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-119.5 ± 0.65	kJ/mol	Chyd	Rogers, Crooks, et al., 1987	liquid phase; ALS
Δ_rH°	-116.1 ± 0.54	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-116.1 ± 0.54	kJ/mol	Eqk	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-120.1 ± 0.3	kJ/mol	Chyd	Turner and Garner, 1957, 2	liquid phase; solvent: Acetic acid; ALS

Hydrogen + =

By formula: H₂ + C₇H₁₂ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-110. ± 0.4	kJ/mol	Chyd	Roth and Lennartz, 1980	liquid phase; solvent: Cyclohexane; ALS
Δ_rH°	-108.2 ± 0.4	kJ/mol	Chyd	Turner, Meador, et al., 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-108.9 ± 0.63	kJ/mol	Chyd	Conn, Kistiakowsky, et al., 1939	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -111.0 ± 0.08 kJ/mol; At 355 K; ALS

3 Hydrogen + =

By formula: 3H₂ + C₇H₈ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-305. ± 0.4	kJ/mol	Chyd	Roth, Klaerner, et al., 1983	liquid phase; solvent: Isooctane; ALS
Δ_rH°	-294.9 ± 1.6	kJ/mol	Chyd	Turner, Meador, et al., 1957	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-301.7 ± 1.3	kJ/mol	Chyd	Conn, Kistiakowsky, et al., 1939	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -304.8 ± 0.04 kJ/mol; at 355 K; ALS

2 Hydrogen + =

By formula: 2H₂ + C₆H₁₀ = C₆H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-231.4 ± 3.0	kJ/mol	Chyd	Molnar, Rachford, et al., 1984	liquid phase; solvent: Dioxane; ALS
Δ_rH°	-227.0 ± 2.8	kJ/mol	Chyd	Molnar, Rachford, et al., 1984	liquid phase; solvent: Hexane; ALS
Δ_rH°	-223.4 ± 0.63	kJ/mol	Chyd	Dolliver, Gresham, et al., 1937	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -225.4 ± 0.63 kJ/mol; At 355 °K; ALS

+ 3 Hydrogen =

By formula: C₅H₅N + 3H₂ = C₅H₁₁N

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-193.8 ± 0.75	kJ/mol	Eqk	Hales and Herington, 1957	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -202.2 ± 0.75 kJ/mol; At 400-550 K; ALS
Δ_rH°	-193.0 ± 2.1	kJ/mol	Eqk	Burrows and King, 1935	liquid phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -188.3 kJ/mol; At 423-443 K; ALS

+ Hydrogen =

By formula: C₈H₁₆ + H₂ = C₈H₁₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-107.	kJ/mol	Chyd	Turner, Nettleton, et al., 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-112.9 ± 0.3	kJ/mol	Chyd	Dolliver, Gresham, et al., 1937	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -114.0 ± 0.3 kJ/mol; At 355 °K; ALS
Δ_rH°	-119.6 ± 3.3	kJ/mol	Chyd	Crawford and Parks, 1936	liquid phase; ALS

+ Hydrogen =

By formula: C₃H₆ + H₂ = C₃H₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-123.4 ± 5.0	kJ/mol	Chyd	Kistiakowsky and Nickle, 1951	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -124.9 ± 2.1 kJ/mol; ALS
Δ_rH°	-125.0 ± 0.42	kJ/mol	Chyd	Kistiakowsky, Ruhoff, et al., 1935	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -126.00 ± 0.054 kJ/mol; At 355 °K; ALS

( • ) + Hydrogen = ( • • )

By formula: (Co⁺ • CH₄) + H₂ = (Co⁺ • H₂ • CH₄)

Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	95.8	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993, 2	gas phase; switching reaction(Co+).2H2, Δ_rS(440 K); Kemper, Bushnell, et al., 1993; M

Enthalpy of reaction

Δ_rH° (kJ/mol)	T (K)	Method	Reference	Comment
73. (+3.,-0.)		SIDT	Kemper, Bushnell, et al., 1993, 2	gas phase; switching reaction(Co+).2H2, Δ_rS(440 K); Kemper, Bushnell, et al., 1993; M

Hydrogen + =

By formula: H₂ + C₃H₆O = C₃H₈O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-68.74 ± 0.42	kJ/mol	Cm	Wiberg, Crocker, et al., 1991	liquid phase; ALS
Δ_rH°	-55.23	kJ/mol	Eqk	Buckley and Herington, 1965	gas phase; ALS
Δ_rH°	-55.40 ± 0.42	kJ/mol	Chyd	Dolliver, Gresham, et al., 1938	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -56.1 ± 0.4 kJ/mol; At 355 °K; ALS

( • Hydrogen ) + = ( • • )

By formula: (Co⁺ • H₂) + CH₄ = (Co⁺ • CH₄ • H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	91.2	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993, 2	gas phase; switching reaction(Co+)2H2, Δ_rS(440 K); Kemper, Bushnell, et al., 1993; M

Enthalpy of reaction

Δ_rH° (kJ/mol)	T (K)	Method	Reference	Comment
94.6 (+5.0,-0.)		SIDT	Kemper, Bushnell, et al., 1993, 2	gas phase; switching reaction(Co+)2H2, Δ_rS(440 K); Kemper, Bushnell, et al., 1993; M

+ Hydrogen =

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; ALS
Δ_rH°	-110.1 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-110.1 ± 0.2	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS

Hydrogen + =

By formula: H₂ + C₈H₁₄ = C₈H₁₆

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-144. ± 0.4	kJ/mol	Chyd	Roth, Adamczak, et al., 1991	liquid phase; see Doering, Roth, et al., 1989; ALS
Δ_rH°	-144.0 ± 1.8	kJ/mol	Chyd	Rogers, Von Voithenberg, et al., 1978	liquid phase; solvent: Hexane; ALS
Δ_rH°	-134.9 ± 0.88	kJ/mol	Chyd	Turner and Meador, 1957	liquid phase; solvent: Acetic acid; ALS

( • Hydrogen ) + = ( • 2)

By formula: (Co⁺ • H₂) + H₂ = (Co⁺ • 2H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	75. ± 3.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=71.1 kJ/mol, Δ_rS(300 K)=103. J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	103.	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=71.1 kJ/mol, Δ_rS(300 K)=103. J/mol*K; M

( • 2 Hydrogen ) + = ( • 3)

By formula: (Co⁺ • 2H₂) + H₂ = (Co⁺ • 3H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	44. ± 2.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=40. kJ/mol, Δ_rS(300 K)=85.8 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	85.8	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=40. kJ/mol, Δ_rS(300 K)=85.8 J/mol*K; M

( • 3 Hydrogen ) + = ( • 4)

By formula: (Co⁺ • 3H₂) + H₂ = (Co⁺ • 4H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	44. ± 3.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=40. kJ/mol, Δ_rS(300 K)=105. J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	101.	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=40. kJ/mol, Δ_rS(300 K)=105. J/mol*K; M

( • 4 Hydrogen ) + = ( • 5)

By formula: (Co⁺ • 4H₂) + H₂ = (Co⁺ • 5H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	22. ± 3.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=18. kJ/mol, Δ_rS(300 K)=91.6 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	94.1	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=18. kJ/mol, Δ_rS(300 K)=91.6 J/mol*K; M

( • 5 Hydrogen ) + = ( • 6)

By formula: (Co⁺ • 5H₂) + H₂ = (Co⁺ • 6H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	20. ± 3.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=17. kJ/mol, Δ_rS(300 K)=99.6 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	99.2	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=17. kJ/mol, Δ_rS(300 K)=99.6 J/mol*K; M

( • 6 Hydrogen ) + = ( • 7)

By formula: (Co⁺ • 6H₂) + H₂ = (Co⁺ • 7H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	6. ± 3.	kJ/mol	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=3. kJ/mol; Δ_rS(300 K)=75.3 J/mol*K; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	75.3	J/mol*K	SIDT	Kemper, Bushnell, et al., 1993	gas phase; Δ_rH(0 K)=3. kJ/mol; Δ_rS(300 K)=75.3 J/mol*K; M

(H₃⁺ • 3 Hydrogen ) + = (H₃⁺ • 4)

By formula: (H₃⁺ • 3H₂) + H₂ = (H₃⁺ • 4H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	7.2 ± 0.4	kJ/mol	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rH°	10.	kJ/mol	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	74.9	J/mol*K	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rS°	80.8	J/mol*K	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M

(H₃⁺ • 2 Hydrogen ) + = (H₃⁺ • 3)

By formula: (H₃⁺ • 2H₂) + H₂ = (H₃⁺ • 3H₂)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	13. ± 0.4	kJ/mol	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rH°	16.	kJ/mol	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
Δ_rS°	77.4	J/mol*K	PHPMS	Hiraoka, 1987	gas phase; M
Δ_rS°	84.5	J/mol*K	PHPMS	Hiraoka and Kebarle, 1975	gas phase; M

Hydrogen + =

By formula: H₂ + C₈H₁₆ = C₈H₁₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-118.2 ± 0.4	kJ/mol	Chyd	Rogers, Dejroongruang, et al., 1992	liquid phase; solvent: Cyclohexane; ALS
Δ_rH°	-119.7 ± 2.2	kJ/mol	Chyd	Rogers and Siddiqui, 1975	liquid phase; solvent: n-Hexane; ALS
Δ_rH°	-114.6 ± 0.59	kJ/mol	Chyd	Turner, Jarrett, et al., 1973	liquid phase; solvent: Acetic acid; ALS

2 Hydrogen + =

By formula: 2H₂ + C₈H₁₄ = C₈H₁₈

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-268.7 ± 1.1	kJ/mol	Chyd	Rogers, Dagdagan, et al., 1979	liquid phase; solvent: Hexane; ALS
Δ_rH°	-262.8 ± 0.67	kJ/mol	Chyd	Turner, Jarrett, et al., 1973	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-263.	kJ/mol	Chyd	Sicher, Svoboda, et al., 1966	liquid phase; solvent: Acetic acid; ALS

Hydrogen + =

By formula: H₂ + C₈H₁₄O = C₈H₁₆O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-55.73	kJ/mol	Chyd	Wiberg, Crocker, et al., 1991	liquid phase; ALS
Δ_rH°	-53.14	kJ/mol	Chyd	Wiberg, Crocker, et al., 1991	solid phase; ALS
Δ_rH°	-39.0	kJ/mol	Chyd	Wiberg, Crocker, et al., 1991	gas phase; ALS
Δ_rH°	-53.14 ± 0.59	kJ/mol	Cm	Wiberg, Crocker, et al., 1991	solid phase; ALS

Hydrogen + =

By formula: H₂ + C₇H₁₂ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-111.4 ± 0.37	kJ/mol	Chyd	Rogers, Crooks, et al., 1987	liquid phase; ALS
Δ_rH°	-106.3 ± 0.46	kJ/mol	Chyd	Turner and Garner, 1958	liquid phase; solvent: Acetic acid; ALS
Δ_rH°	-106.3 ± 0.46	kJ/mol	Chyd	Turner and Garner, 1957	liquid phase; solvent: Acetic acid; ALS

2 Hydrogen + =

By formula: 2H₂ + C₇H₁₀ = C₇H₁₄

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-208.9 ± 0.3	kJ/mol	Chyd	Turner, Mallon, et al., 1973	liquid phase; solvent: Glacial acetic acid; ALS
Δ_rH°	-212.4 ± 0.63	kJ/mol	Chyd	Conn, Kistiakowsky, et al., 1939	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -214.5 ± 0.2 kJ/mol; At 355 K; ALS

Hydrogen + =

By formula: H₂ + C₇H₁₀ = C₇H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-137. ± 0.4	kJ/mol	Chyd	Doering, Roth, et al., 1988	gas phase; ALS
Δ_rH°	-141.5 ± 1.2	kJ/mol	Chyd	Rogers, Choi, et al., 1980	liquid phase; solvent: Hexane; Author was aware that data differs from previously reported values; ALS
Δ_rH°	-138.6 ± 0.88	kJ/mol	Chyd	Turner, Meador, et al., 1957	liquid phase; solvent: Acetic acid; ALS

+ Hydrogen =

By formula: C₃H₆O + H₂ = C₃H₈O

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-84.3 ± 0.4	kJ/mol	Cm	Wiberg, Crocker, et al., 1991	liquid phase; solvent: Triglyme; Heat of hydrogenation; ALS
Δ_rH°	-69.55 ± 0.76	kJ/mol	Eqk	Connett, 1972	gas phase; At 473-524 K; ALS
Δ_rH°	-65.77 ± 0.67	kJ/mol	Chyd	Buckley and Cox, 1967	gas phase; ALS

2 Hydrogen + =

By formula: 2H₂ + C₆H₈ = C₆H₁₂

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	-224.4 ± 1.2	kJ/mol	Chyd	Turner, Mallon, et al., 1973	liquid phase; solvent: Glacial acetic acid; ALS
Δ_rH°	-229.6 ± 0.42	kJ/mol	Chyd	Kistiakowsky, Ruhoff, et al., 1936	gas phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -231.7 ± 0.4 kJ/mol; At 355 °K; ALS

(solution) + Hydrogen (solution) = 2 (solution)

By formula: C₁₀Mn₂O₁₀ (solution) + H₂ (solution) = 2C₅HMnO₅ (solution)

Quantity	Value	Units	Method	Reference	Comment
Δ_rH°	36.4 ± 1.3	kJ/mol	EqS	Klingler R.J. and Rathke, 1992	solvent: Supercritical carbon dioxide; Temperature range: 373-463 K; MS

References

Go To: Top, Gas phase thermochemistry data, Phase change data, Reaction thermochemistry data, Notes

Cox, Wagman, et al., 1984
Cox, J.D.; Wagman, D.D.; Medvedev, V.A., CODATA Key Values for Thermodynamics, Hemisphere Publishing Corp., New York, 1984, 1. [all data]

Chase, 1998
Chase, M.W., Jr., NIST-JANAF Themochemical Tables, Fourth Edition, J. Phys. Chem. Ref. Data, Monograph 9, 1998, 1-1951. [all data]

Roder, Childs, et al., 1973
Roder, H.M.; Childs, G.E.; McCarty, R.D.; Angerhofer, P.E., Survey of the Prop. of the Hydrogen Isotopes Below Their Critical Temp, Natl. Bur. Stand. (U. S.), 1973. [all data]

Clusius and Weigand, 1940
Clusius, K.; Weigand, K., Melting Curves of the Gases A, Kr, Xe, CH4, CH3D, CD4, C2H4, C2H6, COS, and PH3 to 200 Atmospheres Pressure. The Chane of Volume on Melting, Z. Phys. Chem., Abt. B, 1940, 46, 1-37. [all data]

Henning and Otto, 1936
Henning, F.; Otto, J., Vapor pressure curves and triple points in the temperature region from 14 to 90 k, Phys. Z., 1936, 37, 633-8. [all data]

Onnes, Crommelin, et al., 1917
Onnes, H.K.; Crommelin, C.-A.; Cath, P.G., Isothermals of di-atomic substances and their binary mixtures. XIX. A preliminary determination of the critical point of hydrogen., Proc. K. Ned. Akad. Wet., 1917, 20, 178-184. [all data]

van Itterbeek, Verbeke, et al., 1964
van Itterbeek, A.; Verbeke, O.; Theewes, F.; Staes, K.; de Boelpaep, J., The Difference in Vapour Pressure Between Normal and Equilibrium Hydrogen. Vapour Pressure of Normal Hydrogen Between 20 ºK and 32 ºK, Physica (Amsterdam), 1964, 30, 6, 1238-1244, https://doi.org/10.1016/0031-8914(64)90114-4 . [all data]

Rathke, Klingler, et al., 1992
Rathke, J.W.; Klingler, R.J.; Krause, T.R., Organometallics, 1992, 11, 585. [all data]

Bor, 1986
Bor, G., Pure & Appl. Chem., 1986, 58, 543. [all data]

Alemdaroglu, Penninger, et al., 1976
Alemdaroglu, N.H.; Penninger, J.M.L.; Oltay, E., Monatsh. Chem., 1976, 107, 1043. [all data]

Ungváry, 1972
Ungváry, F., J. Organometal. Chem., 1972, 36, 363. [all data]

Poë, Sampson, et al., 1993
Poë, A.J.; Sampson, C.N.; Smith, R.T.; Zheng, Y., J. Am. Chem. Soc., 1993, 115, 3174. [all data]

Landrum and Hoff, 1985
Landrum, J.T.; Hoff, C.D., J. Organometal. Chem., 1985, 282, 215. [all data]

Pedley, 1994
Pedley, J.B., Thermodynamic Data and Structures of Organic Compounds; Thermodynamics Research Center Data Series, Vol I, Thermodynamics Research Center, College Station, 1994. [all data]

Hiraoka, 1987
Hiraoka, K., A Determination of the Stabilities of H3+(H2)n with n=1-9 from Measurements of the gas-Phase Ion Equilibria H3+(H2)n-1 + H2 = H3+(H2)n, J. Chem. Phys., 1987, 87, 7, 4048, https://doi.org/10.1063/1.452909 . [all data]

Beuhler, Ehrenson, et al., 1983
Beuhler, R.J.; Ehrenson, S.; Friedman, L., Hydrogen Cluster Ion Equilibria, J. Chem. Phys., 1983, 79, 12, 5982, https://doi.org/10.1063/1.445781 . [all data]

Hiraoka and Kebarle, 1975
Hiraoka, K.; Kebarle, P., A Determination of the Stabilities of H5+, H7+, H9+, and H11+ from Measurement of the Gas Phase Ion Equilibria Hn+ + H2 = H(n + 2)+ (n = 3, 5, 7, 9), J. Chem. Phys., 1975, 62, 6, 2267, https://doi.org/10.1063/1.430751 . [all data]

Bennett and Field, 1972
Bennett, S.L.; Field, F.H., Reversible Reactions of Gaseous Ions. VII. The Hydrogen System, J. Am. Chem. Soc., 1972, 94, 25, 8669, https://doi.org/10.1021/ja00780a003 . [all data]

Shiell, Hu, et al., 2000
Shiell, R.C.; Hu, X.K.; Hu, Q.C.J.; Hepburn, J.W., Threshold Ion-pair Production spectroscopy (TIPPS) of H2 and D2, Faraday Disc. Chem. Soc., 2000, 115, 331, https://doi.org/10.1039/a909428h . [all data]

Pratt, McCormack, et al., 1992
Pratt, S.T.; McCormack, E.F.; Dehmer, J.L.; Dehmer, P.M., Field-Induced Ion-Pair Formation in Molecular Hydrogen, Phys. Rev. Lett., 1992, 68, 5, 584, https://doi.org/10.1103/PhysRevLett.68.584 . [all data]

Gurvich, Veyts, et al.
Gurvich, L.V.; Veyts, I.V.; Alcock, C.B., Hemisphere Publishing, NY, 1989, V. 1 2, Thermodynamic Properties of Individual Substances, 4th Ed. [all data]

Lykke, Murray, et al., 1991
Lykke, K.R.; Murray, K.K.; Lineberger, W.C., Threshold Photodetachment of H-, Phys. Rev. A, 1991, 43, 11, 6104, https://doi.org/10.1103/PhysRevA.43.6104 . [all data]

Allinger, Dodziuk, et al., 1982
Allinger, N.L.; Dodziuk, H.; Rogers, D.W.; Naik, S.N., Heats of hydrogenation and formation of some 5-membered ring compounds by molecular mechanics calculations and direct measurements, Tetrahedron, 1982, 38, 1593-1597. [all data]

Roth and Lennartz, 1980
Roth, W.R.; Lennartz, H.W., Heats of hydrogenation. I. Determination of heats of hydrogenation with an isothermal titration calorimeter, Chem. Ber., 1980, 113, 1806-1817. [all data]

Turner, Jarrett, et al., 1973
Turner, R.B.; Jarrett, A.D.; Goebel, P.; Mallon, B.J., Heats of hydrogenation. 9. Cyclic acetylenes and some miscellaneous olefins, J. Am. Chem. Soc., 1973, 95, 790-792. [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]

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]

Doering, Roth, et al., 1989
Doering, W.E.; Roth, W.R.; Bauer, F.; Breuckmann, R.; Ebbrecht, T.; Herbold, M.; Schmidt, R.; Lennartz, H-W.; Lenoir, D.; Boese, R., Rotational barriers of strained olefines, Chem. Ber., 1989, 122, 1263-1266. [all data]

Rogers, Von Voithenberg, et al., 1978
Rogers, D.W.; Von Voithenberg, H.; Allinger, N.L., Heats of hydrogenation of the cis and trans isomers of cyclooctene, J. Org. Chem., 1978, 43, 360-361. [all data]

Turner and Meador, 1957
Turner, R.B.; Meador, W.R., Heats of hydrogenation. IV. Hydrogenation of some cis- and trans-cycloolefins, J. Am. Chem. Soc., 1957, 79, 4133-4136. [all data]

Conn, Kistiakowsky, et al., 1939
Conn, J.B.; Kistiakowsky, G.B.; Smith, E.A., Heats of organic reactions. VIII. Some further hydrogenations, including those of some acetylenes, J. Am. Chem. Soc., 1939, 61, 1868-1876. [all data]

Wang, Rosini, et al., 1995
Wang, K.; Rosini, G.P.; Nolan, S.P.; Goldman, A.S., J. Am. Chem. Soc., 1995, 117, 5082. [all data]

Rogers, Crooks, et al., 1987
Rogers, D.W.; Crooks, E.; Dejroongruang, K., Enthalpies of hydrogenation of the hexenes, J. Chem. Thermodyn., 1987, 19, 1209-1215. [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]

Turner and Garner, 1957, 2
Turner, R.B.; Garner, R.H., The stability relationship of 1-methyl-cyclopentene and methylenecyclopentane, J. Am. Chem. Soc., 1957, 79, 253. [all data]

Fang and Rogers, 1992
Fang, W.; Rogers, D.W., Enthalpy of hydrogenation of the hexadienes and cis- and trans-1,3,5-hexatriene, J. Org. Chem., 1992, 57, 2294-2297. [all data]

Molnar, Rachford, et al., 1984
Molnar, A.; Rachford, R.; Smith, G.V.; Liu, R., Heats of hydrogenation by a simple and rapid flow calorimetric method, Appl. Catal., 1984, 9, 219-223. [all data]

Turner, Mallon, et al., 1973
Turner, R.B.; Mallon, B.J.; Tichy, M.; Doering, W.v.E.; Roth, W.R.; Schroder, G., Heats of hydrogenation. X. Conjugative interaction in cyclic dienes and trienes, J. Am. Chem. Soc., 1973, 95, 8605-8610. [all data]

Kistiakowsky, Ruhoff, et al., 1936
Kistiakowsky, G.B.; Ruhoff, J.R.; Smith, H.A.; Vaughan, W.E., Heats of organic reactions. IV. Hydrogenation of some dienes and of benzene, J. Am. Chem. Soc., 1936, 58, 146-153. [all data]

Hiraoka and Kebarle, 1976
Hiraoka, K.; Kebarle, P., Stabilities and Energetics of Pentacoordinated Carbonium Ions. The Isomeric C2H7+ Ions and Some Higher Analogues: C3H9+ and C4H11+, J. Am. Chem. Soc., 1976, 98, 20, 6119, https://doi.org/10.1021/ja00436a009 . [all data]

Kemper, Bushnell, et al., 1993
Kemper, P.R.; Bushnell, J.; Von Helden, G.; Bowers, M.T., Co+(H2)n Clusters: Binding Energies and Molecular Parameters, J. Chem Phys., 1993, 97, 1, 52, https://doi.org/10.1021/j100103a012 . [all data]

Haynes and Armentrout, 1996
Haynes, C.L.; Armentrout, P.B., Guided Ion Beam Determination of the Co+ - H2 Bond Dissociation energy, Chem Phys. Let., 1996, 249, 1-2, 64, https://doi.org/10.1016/0009-2614(95)01337-7 . [all data]

Rogers and Skanupong, 1974
Rogers, D.W.; Skanupong, S., Heats of hydrogenation of sixteen terminal monoolefins. The alternating effect, J. Phys. Chem., 1974, 78, 2569-2572. [all data]

Turner, Meador, et al., 1957
Turner, R.B.; Meador, W.R.; Winkler, R.E., Heats of hydrogenation. I. Apparatus and the heats of hydrogenation of bicyclo[2,2,1]heptene, bicyclo[2,2,1]heptadiene, bicyclo[2,2,2]octene and bicyclo[2,2,2]octadiene, J. Am. Chem. Soc., 1957, 79, 4116-4121. [all data]

Roth, Klaerner, et al., 1983
Roth, W.R.; Klaerner, F.G.; Gerit, F.; Grimme, W.; Koeser, H.G.; Busch, R.; Muskulus, B.; Breuckmann, R.; Scholz, B.P.; Lennartz, H.W., Stereochemistry of the bicyclo[2.1.0]pentane ring opening: thermolysis of tricyclo[3.2.0.0(,)]heptane derivatives, Chem. Ber., 1983, 116, 2717-2737. [all data]

Hales and Herington, 1957
Hales, J.L.; Herington, E.F.G., Equilibrium between pyridine and piperidine, Trans. Faraday Soc., 1957, 53, 616-622. [all data]

Burrows and King, 1935
Burrows, G.H.; King, L.A., Jr., The free energy change that accompanies hydrogenation of pyridine to piperidine, J. Am. Chem. Soc., 1935, 57, 1789-1791. [all data]

Turner, Nettleton, et al., 1958
Turner, R.B.; Nettleton, J.E.; Perelman, Heats of Hydrogenation. VI. Heats of hydrogenation of some substituted ethylenes, J. Am. Chem. Soc., 1958, 80, 1430-1433. [all data]

Crawford and Parks, 1936
Crawford, B.L., Jr.; Parks, G.S., The heat of hydrogenation of diisobutylene, J. Am. Chem. Soc., 1936, 58, 373. [all data]

Kistiakowsky and Nickle, 1951
Kistiakowsky, G.B.; Nickle, A.G., Ethane-ethylene and propane-propylene equilibria, Faraday Discuss. Chem. Soc., 1951, 10, 175-187. [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]

Kemper, Bushnell, et al., 1993, 2
Kemper, P.R.; Bushnell, J.; Von Koppen, P.; Bowers, M.T., Binding Energies of Co+(H2/CH4/C2H6)1,2,3 Clusters, J. Phys. Chem., 1993, 97, 9, 1810, https://doi.org/10.1021/j100111a016 . [all data]

Wiberg, Crocker, et al., 1991
Wiberg, K.B.; Crocker, L.S.; Morgan, K.M., Thermochemical studies of carbonyl compounds. 5. Enthalpies of reduction of carbonyl groups, J. Am. Chem. Soc., 1991, 113, 3447-3450. [all data]

Buckley and Herington, 1965
Buckley, E.; Herington, E.F.G., Equilibria in some secondary alcohol + hydrogen + ketone systems, Trans. Faraday Soc., 1965, 61, 1618-1625. [all data]

Dolliver, Gresham, et al., 1938
Dolliver, M.A.; Gresham, T.L.; Kistiakowsky, G.B.; Smith, E.A.; Vaughan, W.E., Heats of organic reactions. VI. Heats of hydrogenation of some oxygen-containing compounds, J. Am. Chem. Soc., 1938, 60, 440-450. [all data]

Roth, Adamczak, et al., 1991
Roth, W.R.; Adamczak, O.; Breuckmann, R.; Lennartz, H.-W.; Boese, R., Die Berechnung von Resonanzenergien; das MM2ERW-Kraftfeld, Chem. Ber., 1991, 124, 2499-2521. [all data]

Rogers, Dejroongruang, et al., 1992
Rogers, D.W.; Dejroongruang, K.; Samuel, S.D.; Fang, W.; Zhao, Y., Enthalpies of hydrogenation of the octenes and the methylheptenes, J. Chem. Thermodyn., 1992, 24, 561-565. [all data]

Rogers and Siddiqui, 1975
Rogers, D.W.; Siddiqui, N.A., Heats of hydrogenation of large molecules. I. Esters of unsaturated fatty acids, J. Phys. Chem., 1975, 79, 574-577. [all data]

Rogers, Dagdagan, et al., 1979
Rogers, D.W.; Dagdagan, O.A.; Allinger, N.L., Heats of hydrogenation and formation of linear alkynes and a molecular mechanics interpretation, J. Am. Chem. Soc., 1979, 101, 671-676. [all data]

Sicher, Svoboda, et al., 1966
Sicher, J.; Svoboda, M.; Zavada, J.; Turner, R.B.; Goebel, P., Sterochemical studies - XXXVI. An approach to conformational analysis of medium ring compounds. Unsaturated ten-membered ring derivates, Tetrahedron, 1966, 22, 659-671. [all data]

Doering, Roth, et al., 1988
Doering, W.E.; Roth, W.R.; Breuckmann, R.; Figge, L.; Lennartz, H.-W.; Fessner, W.-D.; Prinzbach, F.H., Verbotene Reaktionen. - [2 + 2]-Cycloreversion starrer Cyclobutane, Chem. Ber., 1988, 121, 1-9. [all data]

Rogers, Choi, et al., 1980
Rogers, D.W.; Choi, L.S.; Girellini, R.S., Heats of hydrogenation and formation of quadricyclene, norbornadiene, norbornene, and nortricyclene, J. Phys. Chem., 1980, 84, 1810-1814. [all data]

Connett, 1972
Connett, J.E., Chemical equilibria. 5. Measurement of equilibrium constants for the dehydrogenation of propanol by a vapour flow technique, J. Chem. Thermodyn., 1972, 4, 233-237. [all data]

Buckley and Cox, 1967
Buckley, E.; Cox, J.D., Chemical equilibria. Part 2.-Dehydrogenation of propanol and butanol, Trans. Faraday Soc., 1967, 63, 895-901. [all data]

Klingler R.J. and Rathke, 1992
Klingler R.J.; Rathke, J.W., Inorg. Chem., 1992, 31, 804. [all data]

Notes

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

Symbols used in this document:

P_c	Critical pressure
P_triple	Triple point pressure
S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
T_c	Critical temperature
T_triple	Triple point temperature
Δ_rG°	Free energy of reaction at standard conditions
Δ_rH°	Enthalpy of reaction at standard conditions
Δ_rS°	Entropy of reaction at standard conditions
ρ_c	Critical density

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
Customer support for NIST Standard Reference Data products.