Oxygen

Formula: O₂
Molecular weight: 31.9988
IUPAC Standard InChI:
InChI=1S/O2/c1-2

Download the identifier in a file.
IUPAC Standard InChIKey: MYMOFIZGZYHOMD-UHFFFAOYSA-N
CAS Registry Number: 7782-44-7
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: Molecular oxygen; Oxygen molecule; Pure oxygen; O2; Liquid oxygen; UN 1072; UN 1073; Dioxygen
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Information on this page:
Other data available:
- Phase change data
- Reaction thermochemistry data: reactions 51 to 70
- Henry's Law data
- Gas phase ion energetics data
- Ion clustering data
- Mass spectrum (electron ionization)
- Constants of diatomic molecules
- Fluid Properties
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Gas phase thermochemistry data

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

Quantity	Value	Units	Method	Reference	Comment
S°_{gas,1 bar}	205.152 ± 0.005	J/mol*K	Review	Cox, Wagman, et al., 1984	CODATA Review value
S°_{gas,1 bar}	205.15	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.

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View table.

Temperature (K)	100. - 700.	700. - 2000.	2000. - 6000.
A	31.32234	30.03235	20.91111
B	-20.23531	8.772972	10.72071
C	57.86644	-3.988133	-2.020498
D	-36.50624	0.788313	0.146449
E	-0.007374	-0.741599	9.245722
F	-8.903471	-11.32468	5.337651
G	246.7945	236.1663	237.6185
H	0.0	0.0	0.0
Reference	Chase, 1998	Chase, 1998	Chase, 1998
Comment	Data last reviewed in March, 1977; New parameter fit January 2009	Data last reviewed in March, 1977; New parameter fit January 2009	Data last reviewed in March, 1977; New parameter fit January 2009

Reaction thermochemistry data

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

Data compiled as indicated in comments:
B - John E. Bartmess
M - Michael M. Meot-Ner (Mautner) and Sharon G. Lias
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.

Reactions 1 to 50

+ Oxygen = ( Oxygen )

By formula: O₂^- + O₂ = (O₂^- O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	48. ± 20.	kJ/mol	AVG	N/A	Average of 5 out of 7 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
_rS°	102.	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	130.	J/mol*K	PHPMS	Conway and Nesbit, 1968	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rG°	13. ± 4.6	kJ/mol	TDAs	Hiraoka, 1888	gas phase; see also Sherwood, Hanold, et al., 1996. Aquino, Taylor, et al., 2001 calns indicate rectangular anion; B
_rG°	23. ± 4.2	kJ/mol	IMRE	Payzant J.D. and Kebarle, 1972	gas phase; B
_rG°	13. ± 4.2	kJ/mol	IMRE	Pack and Phelps, 1971	gas phase; B
_rG°	16.7 ± 2.1	kJ/mol	IMRE	Parkes, 1971	gas phase; B
_rG°	16. ± 4.2	kJ/mol	TDAs	Conway and Nesbit, 1968	gas phase; B

Free energy of reaction

_rG° (kJ/mol)	T (K)	Method	Reference	Comment
15.	300.	DT	Pack and Phelps, 1971	gas phase; M

+ Oxygen = ( Oxygen )

By formula: O₂⁺ + O₂ = (O₂⁺ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	41. ± 5.	kJ/mol	AVG	N/A	Average of 5 out of 6 values; Individual data points
Quantity	Value	Units	Method	Reference	Comment
_rS°	78.7	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	104.7	J/mol*K	PHPMS	Conway and Janik, 1970	gas phase; M
_rS°	84.	J/mol*K	PHPMS	Durden, Kebarle, et al., 1969	gas phase; M
_rS°	86.2	J/mol*K	PHPMS	Yang and Conway, 1964	gas phase; M

Free energy of reaction

_rG° (kJ/mol)	T (K)	Method	Reference	Comment
16.	300.	DT	Rakshit and Warneck, 1981	gas phase; M
14.	300.	DT	Rakshit and Warneck, 1980	gas phase; M
14.	296.	FA	Howard, Bierbaum, et al., 1972	gas phase; M
25.	200.	FA	Adams and Bohme, 1970	gas phase; M

(HO₂⁺ 2 Oxygen ) + Oxygen = (HO₂⁺ 3 Oxygen )

By formula: (HO₂⁺ 2O₂) + O₂ = (HO₂⁺ 3O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	11. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
_rH°	13.	kJ/mol	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	76.6	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M
_rS°	84.	J/mol*K	N/A	Hiraoka, Saluja, et al., 1979	gas phase; Entropy change calculated or estimated; M

Free energy of reaction

_rG° (kJ/mol)	T (K)	Method	Reference	Comment
4.6	105.	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; Entropy change calculated or estimated; M

( 7 Oxygen ) + = ( 8 Oxygen )

By formula: (O₂^- 7N₂ O₂) + N₂ = (O₂^- 8N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7. ± 1.	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
_rH°	6.40	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	74.9	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M
_rS°	75.3	J/mol*K	N/A	Hiraoka, 1988, 2	gas phase; Entropy change calculated or estimated; M

O^- + Oxygen = (O^- Oxygen )

By formula: O^- + O₂ = (O^- O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	130.	kJ/mol	PDiss	Hiller and Vestal, 1981	gas phase; From thermochemical cycle, «DELTA»_rH<; M
_rH°	163.	kJ/mol	PES	Novich, Engelking, et al., 1979	gas phase; From thermochemical cycle, from EA(O3), D(O-O2) AND EA(O); M
_rH°	160.	kJ/mol	PDiss	Cosby, Moseley, et al., 1978	gas phase; M
_rH°	180.	kJ/mol	CID	Lifschitz, Wu, et al., 1978	gas phase; M

( Oxygen ) + Oxygen = ( 2 Oxygen )

By formula: (O₂⁺ O₂) + O₂ = (O₂⁺ 2O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	25. ± 1.	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
_rH°	28.7 ± 0.3	kJ/mol	PHPMS	Conway and Janik, 1970	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	110.	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	133.0	J/mol*K	PHPMS	Conway and Janik, 1970	gas phase; M

(HO₂⁺ Oxygen ) + Oxygen = (HO₂⁺ 2 Oxygen )

By formula: (HO₂⁺ O₂) + O₂ = (HO₂⁺ 2O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	29. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
_rH°	28.	kJ/mol	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	96.7	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M
_rS°	92.	J/mol*K	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; M

( 3 Oxygen ) + Oxygen = ( 4 Oxygen )

By formula: (O₂⁺ 3O₂) + O₂ = (O₂⁺ 4O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	9.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
_rH°	10.3 ± 0.75	kJ/mol	PHPMS	Conway and Janik, 1970	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	88.7	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	100.	J/mol*K	PHPMS	Conway and Janik, 1970	gas phase; M

( 2 Oxygen ) + Oxygen = ( 3 Oxygen )

By formula: (O₂⁺ 2O₂) + O₂ = (O₂⁺ 3O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	10.4 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
_rH°	10.6 ± 0.4	kJ/mol	PHPMS	Conway and Janik, 1970	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	78.2	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	82.8	J/mol*K	PHPMS	Conway and Janik, 1970	gas phase; M

( 4 Oxygen ) + Oxygen = ( 5 Oxygen )

By formula: (O₂⁺ 4O₂) + O₂ = (O₂⁺ 5O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
_rH°	8. ± 3.	kJ/mol	PHPMS	Conway and Janik, 1970	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	89.5	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M
_rS°	71.1	J/mol*K	PHPMS	Conway and Janik, 1970	gas phase; M

O₃^- + Oxygen = (O₃^- Oxygen )

By formula: O₃^- + O₂ = (O₃^- O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8.79 ± 0.84	kJ/mol	TDAs	Hiraoka, 1988, 2	gas phase; B,M
Quantity	Value	Units	Method	Reference	Comment
_rS°	79.5	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rG°	-15.1 ± 2.1	kJ/mol	TDAs	Hiraoka, 1988, 2	gas phase; B

+ Oxygen = ( Oxygen )

By formula: NO^- + O₂ = (NO^- O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	12.1 ± 0.8	kJ/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	60.7	J/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

Free energy of reaction

_rG° (kJ/mol)	T (K)	Method	Reference	Comment
-2.	200.	FA	Dunkin, Fehsenfeld, et al., 1971	gas phase; DG>; M

( 6 Oxygen ) + Oxygen = ( 7 Oxygen )

By formula: (O₂^- 6O₂) + O₂ = (O₂^- 7O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	5.86	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	67.	J/mol*K	N/A	Hiraoka, 1988	gas phase; Entropy change calculated or estimated; M

( 7 Oxygen ) + Oxygen = ( 8 Oxygen )

By formula: (O₂⁺ 7O₂) + O₂ = (O₂⁺ 8O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7.61	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; Entropy change calculated or estimated; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	92.	J/mol*K	N/A	Hiraoka, 1988	gas phase; Entropy change calculated or estimated; M

( Oxygen ) + = ( Oxygen )

By formula: (O₂⁺ O₂) + N₂ = (O₂⁺ N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	12.	kJ/mol	HPMS	Speller and Fitaire, 1983	gas phase; Entropy change is questionable; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	42.3	J/mol*K	HPMS	Speller and Fitaire, 1983	gas phase; Entropy change is questionable; M

(H₃⁺ Oxygen ) + Oxygen = (H₃⁺ 2 Oxygen )

By formula: (H₃⁺ O₂) + O₂ = (H₃⁺ 2O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	48.1	kJ/mol	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; From thermochemical cycle(O2H+)O2; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	92.	J/mol*K	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; From thermochemical cycle(O2H+)O2; M

(O₃^- 4 Oxygen ) + Oxygen = (O₃^- 5 Oxygen )

By formula: (O₃^- 4O₂) + O₂ = (O₃^- 5O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	6.44	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; «DELTA»_rH, «DELTA»_rS approximate; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	68.6	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; «DELTA»_rH, «DELTA»_rS approximate; M

H₃⁺ + Oxygen = (H₃⁺ Oxygen )

By formula: H₃⁺ + O₂ = (H₃⁺ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	52.3	kJ/mol	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; From thermochemical cycle(O2H+)O2; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	82.0	J/mol*K	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; From thermochemical cycle(O2H+)O2; M

(O₂S^- 2 Oxygen ) + = (O₂S^- 3 Oxygen )

By formula: (O₂S^- 2O₂S O₂) + O₂S = (O₂S^- 3O₂S O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	15.1 ± 1.7	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
_rG°	6. ± 13.	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B

(O₂S^- Oxygen ) + = (O₂S^- 2 Oxygen )

By formula: (O₂S^- O₂S O₂) + O₂S = (O₂S^- 2O₂S O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	19.2 ± 1.7	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
_rG°	10. ± 8.4	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B

(O₃S^- Oxygen ) + = (O₃S^- 2 Oxygen )

By formula: (O₃S^- O₂S O₂) + O₂S = (O₃S^- 2O₂S O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	23.8 ± 2.5	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
_rG°	15. ± 8.8	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B

+ Oxygen = ( Oxygen )

By formula: O⁺ + O₂ = (O⁺ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	179.	kJ/mol	PDiss	Hiller and Vestal, 1982	gas phase; M
_rH°	200.	kJ/mol	PI	Linn, Ono, et al., 1981	gas phase; M
_rH°	209.	kJ/mol	PDiss	Mosely, Ozenne, et al., 1981	gas phase; M

(O₃S^- Oxygen ) + = (O₃S^- Oxygen )

By formula: (O₃S^- O₂) + O₂S = (O₃S^- O₂S O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	27.2 ± 3.3	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
_rG°	18. ± 9.2	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B

(O₂S^- Oxygen ) + = (O₂S^- Oxygen )

By formula: (O₂S^- O₂) + O₂S = (O₂S^- O₂S O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	46.0 ± 4.2	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B
Quantity	Value	Units	Method	Reference	Comment
_rG°	26. ± 9.2	kJ/mol	TDAs	Vacher, Jorda, et al., 1992	gas phase; B

( 2 Oxygen ) + = ( 3 Oxygen )

By formula: (O₂^- 2N₂ O₂) + N₂ = (O₂^- 3N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	10.3 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	76.6	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( 3 Oxygen ) + = ( 4 Oxygen )

By formula: (O₂^- 3N₂ O₂) + N₂ = (O₂^- 4N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	9.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	78.2	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( 4 Oxygen ) + = ( 5 Oxygen )

By formula: (O₂^- 4N₂ O₂) + N₂ = (O₂^- 5N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8.1 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	81.6	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( 5 Oxygen ) + = ( 6 Oxygen )

By formula: (O₂^- 5N₂ O₂) + N₂ = (O₂^- 6N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7.6 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	81.6	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( 6 Oxygen ) + = ( 7 Oxygen )

By formula: (O₂^- 6N₂ O₂) + N₂ = (O₂^- 7N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7.1 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	78.7	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( Oxygen ) + = ( 2 Oxygen )

By formula: (O₂^- N₂ O₂) + N₂ = (O₂^- 2N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	11.7 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	74.9	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

( 2 Oxygen ) + Oxygen = ( 3 Oxygen )

By formula: (NO^- 2O₂) + O₂ = (NO^- 3O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	11.8 ± 0.8	kJ/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	65.7	J/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( 3 Oxygen ) + Oxygen = ( 4 Oxygen )

By formula: (NO^- 3O₂) + O₂ = (NO^- 4O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	10.2 ± 0.8	kJ/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	67.4	J/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( 4 Oxygen ) + Oxygen = ( 5 Oxygen )

By formula: (NO^- 4O₂) + O₂ = (NO^- 5O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	9.8 ± 0.8	kJ/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	80.3	J/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

( Oxygen ) + Oxygen = ( 2 Oxygen )

By formula: (NO^- O₂) + O₂ = (NO^- 2O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	12.1 ± 0.8	kJ/mol	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	65.7	J/mol*K	PHPMS	Hiraoka and Yamabe, 1991	gas phase; M

(HO₂⁺ 3 Oxygen ) + Oxygen = (HO₂⁺ 4 Oxygen )

By formula: (HO₂⁺ 3O₂) + O₂ = (HO₂⁺ 4O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	11. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	88.3	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ 4 Oxygen ) + Oxygen = (HO₂⁺ 5 Oxygen )

By formula: (HO₂⁺ 4O₂) + O₂ = (HO₂⁺ 5O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	9. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	91.6	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ 5 Oxygen ) + Oxygen = (HO₂⁺ 6 Oxygen )

By formula: (HO₂⁺ 5O₂) + O₂ = (HO₂⁺ 6O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	93.3	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ 6 Oxygen ) + Oxygen = (HO₂⁺ 7 Oxygen )

By formula: (HO₂⁺ 6O₂) + O₂ = (HO₂⁺ 7O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	94.1	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ 7 Oxygen ) + Oxygen = (HO₂⁺ 8 Oxygen )

By formula: (HO₂⁺ 7O₂) + O₂ = (HO₂⁺ 8O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	88.3	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ 8 Oxygen ) + Oxygen = (HO₂⁺ 9 Oxygen )

By formula: (HO₂⁺ 8O₂) + O₂ = (HO₂⁺ 9O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7. ± 1.	kJ/mol	PHPMS	Hiraoka and Mori, 1989	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	86.2	J/mol*K	PHPMS	Hiraoka and Mori, 1989	gas phase; M

(HO₂⁺ Oxygen ) + = (HO₂⁺ Oxygen )

By formula: (HO₂⁺ O₂) + H₂ = (HO₂⁺ H₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	17.	kJ/mol	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	71.	J/mol*K	PHPMS	Hiraoka, Saluja, et al., 1979	gas phase; M

( Oxygen ) + = ( Oxygen )

By formula: (O₂^- O₂) + N₂ = (O₂^- N₂ O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	12.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988, 2	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	69.0	J/mol*K	PHPMS	Hiraoka, 1988, 2	gas phase; M

2 + Oxygen = 2

By formula: 2C₂H₆S + O₂ = 2C₂H₆OS

Quantity	Value	Units	Method	Reference	Comment
_rH°	-277.7 ± 0.84	kJ/mol	Cm	Douglas, 1946	liquid phase; Reanalyzed by Cox and Pilcher, 1970, Original value = -278.3 ± 0.8 kJ/mol; At 291°K; ALS

= + 0.5 Oxygen

By formula: C₂H₆O₂S = C₂H₆OS + 0.5O₂

Quantity	Value	Units	Method	Reference	Comment
_rH°	243.3 ± 0.84	kJ/mol	Cm	Douglas, 1946	liquid phase; Reanalyzed by Cox and Pilcher, 1970, Original value = 246.9 ± 0.8 kJ/mol; At 291°K; ALS

( 2 Oxygen ) + Oxygen = ( 3 Oxygen )

By formula: (O₂^- 2O₂) + O₂ = (O₂^- 3O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	10.0 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	89.1	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

( 3 Oxygen ) + Oxygen = ( 4 Oxygen )

By formula: (O₂^- 3O₂) + O₂ = (O₂^- 4O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	7. ± 1.	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	64.4	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

( 4 Oxygen ) + Oxygen = ( 5 Oxygen )

By formula: (O₂^- 4O₂) + O₂ = (O₂^- 5O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	6.4 ± 0.8	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	64.4	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

( 5 Oxygen ) + Oxygen = ( 6 Oxygen )

By formula: (O₂^- 5O₂) + O₂ = (O₂^- 6O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	6. ± 1.	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	67.8	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

( 5 Oxygen ) + Oxygen = ( 6 Oxygen )

By formula: (O₂⁺ 5O₂) + O₂ = (O₂⁺ 6O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8. ± 1.	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	90.8	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

( 6 Oxygen ) + Oxygen = ( 7 Oxygen )

By formula: (O₂⁺ 6O₂) + O₂ = (O₂⁺ 7O₂)

Quantity	Value	Units	Method	Reference	Comment
_rH°	8. ± 2.	kJ/mol	PHPMS	Hiraoka, 1988	gas phase; M
Quantity	Value	Units	Method	Reference	Comment
_rS°	91.6	J/mol*K	PHPMS	Hiraoka, 1988	gas phase; M

References

Go To: Top, Gas phase thermochemistry 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]

Hiraoka, 1988
Hiraoka, K., A Determination of the Stabilities of O2+(O2)n and O2-(O2)n with n = 1 - 8 from Measurements of the Gas-Phase Ion Equilibria, J. Chem. Phys., 1988, 89, 5, 3190, https://doi.org/10.1063/1.454976 . [all data]

Conway and Nesbit, 1968
Conway, D.C.; Nesbit, L.E., Stability of O₄^-, J. Chem. Phys., 1968, 48, 1, 509, https://doi.org/10.1063/1.1667956 . [all data]

Hiraoka, 1888
Hiraoka, K., A Determination of the Stability of O₂⁺(O₂)n and O₂^-(O₂)n with n=1-8 from Measurements of the Gas Phase Ion Equilibria, J. Chem. Phys., 1888, 89, 5, 3190, https://doi.org/10.1063/1.454976 . [all data]

Sherwood, Hanold, et al., 1996
Sherwood, C.R.; Hanold, K.A.; Garner, M.C.; Strong, K.M.; Continetti, R.E., Translational Spectroscopy Studies of the Photodissociation Dynamics of O4-, J. Chem. Phys., 1996, 105, 24, 10803, https://doi.org/10.1063/1.472888 . [all data]

Aquino, Taylor, et al., 2001
Aquino, A.J.A.; Taylor, P.R.; Walch, S.P., Structure, properties, and photodissociation of O-4(-), J. Chem. Phys., 2001, 114, 7, 3010-3017, https://doi.org/10.1063/1.1288379 . [all data]

Payzant J.D. and Kebarle, 1972
Payzant J.D.; Kebarle, P., Kinetics and Reactions Leading to O2-(H2O)n in Moist Oxygen, J. Chem. Phys., 1972, 56, 7, 3482, https://doi.org/10.1063/1.1677723 . [all data]

Pack and Phelps, 1971
Pack, J.L.; Phelps, A.V., Hydration of Oxygen Negative Ions, Bull. Am. Phys. Soc., 1971, 16, 214. [all data]

Parkes, 1971
Parkes, D.A., Electron Attachment and Negative Ion-Molecule Reactions in Pure O₂, Trans. Farad. Soc., 1971, 97, 711, https://doi.org/10.1039/tf9716700711 . [all data]

Conway and Janik, 1970
Conway, D.C.; Janik, G.S., Determination of the Bond Energies for the Series O2 - O2+ through O2 - O10+, J. Chem. Phys., 1970, 53, 5, 1859, https://doi.org/10.1063/1.1674262 . [all data]

Durden, Kebarle, et al., 1969
Durden, D.A.; Kebarle, P.; Good, A., Thermal Ion-Molecule Reaction Rate Constants at Pressures up to 10 torr with a Pulsed Mass Spectrometer. Reactions in Methane, Krypton, and Oxygen, J. Chem. Phys., 1969, 50, 2, 805, https://doi.org/10.1063/1.1671133 . [all data]

Yang and Conway, 1964
Yang, J.H.; Conway, D.C., Bonding in Ion Clusters. I. O4+, J. Chem. Phys., 1964, 40, 6, 1729, https://doi.org/10.1063/1.1725389 . [all data]

Rakshit and Warneck, 1981
Rakshit, A.B.; Warneck, P., Formation and Reactions of O2+.CO2, O2+.H2O and O2+(CO2)2 Ions, Int. J. Mass Spectrom Ion Phys., 1981, 40, 2, 135, https://doi.org/10.1016/0020-7381(81)80037-X . [all data]

Rakshit and Warneck, 1980
Rakshit, A.B.; Warneck, P., A Drift Chamber Study of the Formation of Water Cluster Ions in Oxygen, J. Chem. Phys., 1980, 73, 10, 5074, https://doi.org/10.1063/1.439985 . [all data]

Howard, Bierbaum, et al., 1972
Howard, C.J.; Bierbaum, V.M.; Rundle, H.W.; Kaufman, F., Kinetics and Mechanism of Formation of Water Cluster Ions from O2+ and H2O+, J. Chem. Phys., 1972, 57, 8, 3491, https://doi.org/10.1063/1.1678783 . [all data]

Adams and Bohme, 1970
Adams, N.G.; Bohme, D., Flowing Afterglow Studies of Formation and Reactions of Cluster Ions of O₂⁺, O₂^-, and O^-, J. Chem. Phys., 1970, 52, 6, 3133, https://doi.org/10.1063/1.1673449 . [all data]

Hiraoka and Mori, 1989
Hiraoka, K.; Mori, T., Gas Phase Stabilities of the Cluster Ions H+(CO)2(CO)n, H+(N2)2(N2)n and H+(O2)2(O2)n with n = 1 - 14, Chem. Phys., 1989, 137, 1-3, 345, https://doi.org/10.1016/0301-0104(89)87119-8 . [all data]

Hiraoka, Saluja, et al., 1979
Hiraoka, K.; Saluja, P.P.S.; Kebarle, P., Stabilities of Complexes (N2)nH+, (CO)nH+ and (O2)nH+ for n = 1 to 7 Based on Gas Phase Ion Equilibrium Measurements, Can. J. Chem., 1979, 57, 16, 2159, https://doi.org/10.1139/v79-346 . [all data]

Hiraoka, 1988, 2
Hiraoka, K., Determination of the Stabilities of O₃^-(N₂)n, O₃^-(O₂)n, and O₄^-(N₂)n from Measurements of the Gas Phase Equilibria, Chem. Phys., 1988, 125, 2-3, 439, https://doi.org/10.1016/0301-0104(88)87096-4 . [all data]

Hiller and Vestal, 1981
Hiller, J.F.; Vestal, M.L., Laser Photodissociation of O3- by Triple Quadrupole Mass Spectrometry, J. Chem. Phys., 1981, 74, 11, 6096, https://doi.org/10.1063/1.441053 . [all data]

Novich, Engelking, et al., 1979
Novich, S.E.; Engelking, P.C.; Jones, P.L.; Futrell, J.H.; Lineberger, W.C., Laser photoelectron, photodetachment, and photodestruction spectra of O₃-, J. Chem. Phys., 1979, 70, 2652. [all data]

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Lifschitz, Wu, et al., 1978
Lifschitz, C.; Wu, R.L.C.; Tiernan, T.O.; Terwillinger, D.T., Negative Ion - Molecule Reactions of Ozone and Their Implications on the Thermochemistry of O3-, J. Chem. Phys., 1978, 68, 1, 247, https://doi.org/10.1063/1.435489 . [all data]

Hiraoka and Yamabe, 1991
Hiraoka, K.; Yamabe, S., Cluster Ions: Gas Phase Stabilities of NO+(O2)n and NO+(CO2)n with n = 1 - 5, J. Chem. Phys., 1991, 95, 9, 6800, https://doi.org/10.1063/1.461518 . [all data]

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Dunkin, D.B.; Fehsenfeld, F.C.; Schelmetekopf, A.L.; Ferguson, E.E., Three-Body Association Reactions of NO+ with O2, N2, and CO2, J. Chem. Phys., 1971, 54, 9, 3817, https://doi.org/10.1063/1.1675432 . [all data]

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Speller, C.V.; Fitaire, M., Proceedings of the 16th International Conference on Phenomena of Ionized Gases, H. Boetticher, H. Wenk and E. Shulz - Gulde, ed(s)., ICPIG, Dusseldorf, 1983, 568. [all data]

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Hiller, J.F.; Vestal, M.L., Laser Photodissociation of O3+ and the Energetics of Ozone and its Ions, J. Chem. Phys., 1982, 77, 3, 1248, https://doi.org/10.1063/1.444000 . [all data]

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Linn, S.H.; Ono, Y.; Ng, C.Y., A Study of the Ion - Molecule Half Reactions O2+(a4piu, v)...(O2)m ---> O2m+1 + O, m=1, 2, 3, Using the Molecular Beam Photoionization Method, J. Chem. Phys., 1981, 74, 6, 3348, https://doi.org/10.1063/1.441487 . [all data]

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Douglas, T.B., Heats of formation of liquid methyl sulfoxide and crystalline methyl sulfone at 18°, J. Am. Chem. Soc., 1946, 68, 1072-1076. [all data]

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Notes

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

Symbols used in this document:

S°_{gas,1 bar}	Entropy of gas at standard conditions (1 bar)
T	Temperature
_rG°	Free energy of reaction at standard conditions
_rH°	Enthalpy of reaction at standard conditions
_rS°	Entropy of reaction at standard conditions

Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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