Bromine
- Formula: Br2
- Molecular weight: 159.808
- IUPAC Standard InChIKey: GDTBXPJZTBHREO-UHFFFAOYSA-N
- CAS Registry Number: 7726-95-6
- Chemical structure:
This structure is also available as a 2d Mol file or as a computed 3d SD file
View 3d structure (requires JavaScript / HTML 5) - Other names: Br2; Brom; Brome; Bromo; Broom; UN 1744; Dibromine
- Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Reaction thermochemistry data: reactions 1 to 50, reactions 51 to 55
- Gas phase ion energetics data
- Mass spectrum (electron ionization)
- Constants of diatomic molecules
- Data at other public NIST sites:
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- NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
- NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)
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Gas phase thermochemistry data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | 7.388 ± 0.026 | kcal/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
ΔfH°gas | 7.388 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1982 |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 58.668 ± 0.001 | cal/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
S°gas,1 bar | 58.647 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1982 |
Gas Phase Heat Capacity (Shomate Equation)
Cp° = 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
Cp = heat capacity (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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Temperature (K) | 332.503 to 3400. | 3400. to 6000. |
---|---|---|
A | 9.208229 | 8.363500 |
B | -0.472475 | 2.211341 |
C | 0.364748 | -0.564433 |
D | -0.047418 | 0.036887 |
E | -0.044411 | -10.29550 |
F | 4.511521 | -1.784841 |
G | 69.66690 | 65.39921 |
H | 7.387670 | 7.387670 |
Reference | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in June, 1982 | Data last reviewed in June, 1982 |
Condensed phase thermochemistry data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
S°liquid | 36.379 ± 0.072 | cal/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
Phase change data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tfus | 266.0 | K | N/A | Weber, 1912 | Uncertainty assigned by TRC = 0.3 K; TRC |
Tfus | 254.15 | K | N/A | Serullas, 1827 | Uncertainty assigned by TRC = 10. K; TRC |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
7.12 | 358. | N/A | Blair and Ihle, 1973 | Based on data from 343. to 383. K.; AC |
7.48 | 312. | N/A | Fischer and Bingle, 1955 | Based on data from 297. to 389. K.; AC |
4.21 | 206. | C | Giauque and Wiebe, 1928 | AC |
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 |
---|---|---|---|---|---|
343. to 383. | 4.70256 | 1562.264 | 0.628 | Blair and Ihle, 1973 | Coefficents calculated by NIST from author's data. |
224.5 to 331.4 | 2.93958 | 638.258 | -115.144 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Ion clustering data
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Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
Data compiled by: John E. Bartmess
Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. Searches may be limited to ion clustering reactions. A general reaction search form is also available.
Clustering reactions
By formula: Br- + Br2 = (Br- • Br2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 30.4 ± 1.7 | kcal/mol | CIDT | Nizzi, Pommerening, et al., 1998 | gas phase |
ΔrH° | 33.70 | kcal/mol | N/A | Check, Faust, et al., 2001 | gas phase; Fe-; ; ΔS(EA)=5.8 |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 22.50 | kcal/mol | N/A | Check, Faust, et al., 2001 | gas phase; Fe-; ; ΔS(EA)=5.8 |
By formula: Br3- + Br2 = (Br3- • Br2)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 9.1 ± 1.7 | kcal/mol | CIDT | Nizzi, Pommerening, et al., 1998 | gas phase |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Ion clustering data, Notes
Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.
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]
Weber, 1912
Weber, H.C.P.,
J. Am. Chem. Soc., 1912, 34, 1294. [all data]
Serullas, 1827
Serullas,
New Compounds of Bromine. Ethyl Bromide ("Ether Hydro-Bromique"), and Cyanogen Bromide ("Cyanure de Brome"). Solidification of Bromine and of Bromform ("Hydro-carbure de Brome"),
Ann. Chim. Phys., 1827, 34, 95. [all data]
Blair and Ihle, 1973
Blair, A.; Ihle, H.,
The thermal decomposition and thermodynamic properties of uranium pentabromide,
Journal of Inorganic and Nuclear Chemistry, 1973, 35, 11, 3795-3803, https://doi.org/10.1016/0022-1902(73)80071-5
. [all data]
Fischer and Bingle, 1955
Fischer, Jack; Bingle, James,
The Vapor Pressure of Bromine from 24 to 116° 1,
J. Am. Chem. Soc., 1955, 77, 24, 6511-6512, https://doi.org/10.1021/ja01629a026
. [all data]
Giauque and Wiebe, 1928
Giauque, W.F.; Wiebe, R.,
THE HEAT CAPACITY OF HYDROGEN BROMIDE FROM 15°K. TO ITS BOILING POINT AND ITS HEAT OF VAPORIZATION. THE ENTROPY FROM SPECTROSCOPIC DATA,
J. Am. Chem. Soc., 1928, 50, 8, 2193-2202, https://doi.org/10.1021/ja01395a018
. [all data]
Stull, 1947
Stull, Daniel R.,
Vapor Pressure of Pure Substances. Organic and Inorganic Compounds,
Ind. Eng. Chem., 1947, 39, 4, 517-540, https://doi.org/10.1021/ie50448a022
. [all data]
Nizzi, Pommerening, et al., 1998
Nizzi, K.E.; Pommerening, C.A.; Sunderlin, L.S.,
Gas-phase thermochemistry of polyhalide anions,
J. Phys. Chem. A, 1998, 102, 39, 7674-7679, https://doi.org/10.1021/jp9824508
. [all data]
Check, Faust, et al., 2001
Check, C.E.; Faust, T.O.; Bailey, J.M.; Wright, B.J.; Gilbert, T.M.; Sunderlin, L.S.,
Addition of Polarization and Diffuse Functions to the LANL2DZ Basis Set for P-Block Elements,
J. Phys. Chem. A,, 2001, 105, 34, 8111, https://doi.org/10.1021/jp011945l
. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Ion clustering data, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) S°liquid Entropy of liquid at standard conditions Tfus Fusion (melting) point ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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