Chlorine
- Formula: Cl2
- Molecular weight: 70.906
- IUPAC Standard InChIKey: KZBUYRJDOAKODT-UHFFFAOYSA-N
- CAS Registry Number: 7782-50-5
- 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: Cl2; Bertholite; Chloor; Chlor; Chlore; Chlorine mol.; Cloro; Molecular chlorine; UN 1017; Diatomic chlorine
- 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:
- Options:
Data at NIST subscription sites:
- NIST / TRC Web Thermo Tables, "lite" edition (thermophysical and thermochemical data)
- NIST / TRC Web Thermo Tables, professional edition (thermophysical and thermochemical data)
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, Gas phase ion energetics data, References, Notes
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°gas,1 bar | 223.081 ± 0.010 | J/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
S°gas,1 bar | 223.08 | J/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 (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.
Temperature (K) | 298. to 1000. | 1000. to 3000. | 3000. to 6000. |
---|---|---|---|
A | 33.05060 | 42.67730 | -42.55350 |
B | 12.22940 | -5.009570 | 41.68570 |
C | -12.06510 | 1.904621 | -7.126830 |
D | 4.385330 | -0.165641 | 0.387839 |
E | -0.159494 | -2.098480 | 101.1440 |
F | -10.83480 | -17.28980 | 132.7640 |
G | 259.0290 | 269.8400 | 264.7860 |
H | 0.000000 | 0.000000 | 0.000000 |
Reference | Chase, 1998 | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in June, 1982 | Data last reviewed in June, 1982 | Data last reviewed in June, 1982 |
Phase change data
Go To: Top, Gas phase thermochemistry data, Gas phase ion energetics data, References, Notes
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
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 239.5 | K | N/A | Thiele and Schulte, 1920 | Uncertainty assigned by TRC = 0.6 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 172.17 ± 0.05 | K | N/A | Angus, Armstrong, et al., 1984 | Uncertainty assigned by TRC = 0.05 K; TRC |
Ttriple | 172.12 | K | N/A | Giauque and Powell, 1939 | Uncertainty assigned by TRC = 0.15 K; mean of 5 measurements with thermocouple and Pt res. therm., To = 273.10 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ptriple | 0.01392 ± 0.00003 | bar | N/A | Angus, Armstrong, et al., 1984 | Uncertainty assigned by TRC = 0.00003 bar; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tc | 416.956 | K | N/A | Angus, Armstrong, et al., 1984 | TRC |
Tc | 416.9 | K | N/A | Ambrose, Hall, et al., 1979 | Uncertainty assigned by TRC = 0.5 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Pc | 79.914 | bar | N/A | Angus, Armstrong, et al., 1984 | TRC |
Pc | 79.77 | bar | N/A | Ambrose, Hall, et al., 1979 | Uncertainty assigned by TRC = 0.50 bar; Visual, uncertain because of reactivity of element.; TRC |
Quantity | Value | Units | Method | Reference | Comment |
ρc | 8.1344 | mol/l | N/A | Angus, Armstrong, et al., 1984 | 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 |
---|---|---|---|---|---|
155. to 239.4 | 3.0213 | 530.591 | -64.639 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
239.4 to 400.3 | 4.28814 | 969.992 | -12.791 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Phase change data, References, Notes
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:
LL - Sharon G. Lias and Joel F. Liebman
LBLHLM - Sharon G. Lias, John E. Bartmess, Joel F. Liebman, John L. Holmes, Rhoda D. Levin, and W. Gary Mallard
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
B - John E. Bartmess
View reactions leading to Cl2+ (ion structure unspecified)
Electron affinity determinations
EA (eV) | Method | Reference | Comment |
---|---|---|---|
2.50 ± 0.20 | NBIE | Bowen, Liesegang, et al., 1983 | B |
2.33004 | ECD | Ayala, Wentworth, et al., 1981 | Vertical Detachment Energy: 1.02 eV; B |
2.40 ± 0.20 | NBIE | Dispert and Lacmann, 1977 | B |
2.32 ± 0.10 | Endo | Hughes, Lifschitz, et al., 1973 | B |
2.45 ± 0.15 | NBIE | Baeda, 1972 | B |
2.46 ± 0.14 | IMRB | Dunkin, Fehsenfeld, et al., 1972 | B |
2.38 ± 0.10 | Endo | Chupka, Berkowitz, et al., 1971 | B |
2.52 ± 0.17 | EIAE | DeCorpo and Franklin, 1971 | From CCl4; B |
1.020 ± 0.050 | NBIE | Hubers, Kleyn, et al., 1976 | Stated electron affinity is the Vertical Detachment Energy; B |
3.20 ± 0.20 | NBIE | Lacmann and Herschbach, 1970 | B |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
11.481 ± 0.003 | TE | Yencha, Hopkirk, et al., 1995 | LL |
11.480 ± 0.005 | PE | Van Lonkhuyzen and De Lange, 1984 | LBLHLM |
11.50 | EVAL | Huber and Herzberg, 1979 | LLK |
11.51 ± 0.01 | PE | Potts and Price, 1971 | LLK |
11.48 ± 0.01 | PI | Dibeler, Walker, et al., 1971 | LLK |
11.49 | PE | Cornford, Frost, et al., 1971 | LLK |
11.49 | PE | Anderson, Mamantov, et al., 1971 | LLK |
11.48 ± 0.01 | PI | Watanabe, 1957 | RDSH |
11.49 | PE | Dyke, Josland, et al., 1984 | Vertical value; LBLHLM |
11.59 | PE | Kimura, Katsumata, et al., 1981 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
Cl+ | 11.86 ± 0.04 | Cl- | EI | Frost and McDowell, 1959 | RDSH |
References
Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics 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]
Thiele and Schulte, 1920
Thiele, A.; Schulte, E.,
Binary equilibrium systems with solid carbon dioxide,
Z. Phys. Chem., Stoechiom. Verwandtschaftsl., 1920, 96, 312-42. [all data]
Angus, Armstrong, et al., 1984
Angus, S.; Armstrong, B.; de Reuck, K.M.,
International Thermodynamic Tables of the Fluid State - Chlorine, Pergamon, Oxford, 1984. [all data]
Giauque and Powell, 1939
Giauque, W.F.; Powell, T.M.,
Chlorine. The Heat Capacity, Vapor Pressure, Heats of Fusion and Vaporiza- tion, and Entropy,
J. Am. Chem. Soc., 1939, 61, 1970. [all data]
Ambrose, Hall, et al., 1979
Ambrose, D.; Hall, D.J.; Lee, D.A.; Lewis, G.B.,
Vapor pressure of chlorine,
J. Chem. Thermodyn., 1979, 11, 1089. [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]
Bowen, Liesegang, et al., 1983
Bowen, K.H.; Liesegang, G.W.; Sanders, R.A.; Herschbach, D.W.,
Electron Attachment to Molecular Clusters by Collisional Charge Transfer,
J. Phys. Chem., 1983, 87, 4, 557-565, https://doi.org/10.1021/j100227a009
. [all data]
Ayala, Wentworth, et al., 1981
Ayala, J.A.; Wentworth, W.E.; Chen, E.C.M.,
Electron attachment to halogens,
J. Phys. Chem., 1981, 85, 768. [all data]
Dispert and Lacmann, 1977
Dispert, H.; Lacmann, K.,
Chemiionization in alkali-halogen reactions: Evidence for ion formation by alkali dimers,
Chem. Phys. Lett., 1977, 47, 533. [all data]
Hughes, Lifschitz, et al., 1973
Hughes, B.M.; Lifschitz, C.; Tiernan, T.O.,
Electron affinities from endothermic negative-ion charge-transfer reactions. III. NO, NO2, S2, CS2, Cl2, Br2, I2, and C2H,
J. Chem. Phys., 1973, 59, 3162. [all data]
Baeda, 1972
Baeda, A.P.M.,
The adiabatic electron affinities of Cl2, Br2, I2, IBr, NO2, and O2,
Physica, 1972, 59, 541. [all data]
Dunkin, Fehsenfeld, et al., 1972
Dunkin, D.B.; Fehsenfeld, F.C.; Ferguson, F.E.,
Thermal energy rate constants for the reactions NO2- + Cl2 → Cl2-, Cl2- + NO2 Ü Cl-, HS- + NO2 Ü NO2-, HS- + Cl2 Ü Cl2-, and S- + NO2 Ü NO2-,
Chem. Phys. Lett., 1972, 15, 257. [all data]
Chupka, Berkowitz, et al., 1971
Chupka, W.A.; Berkowitz, J.; Gutman, D.,
Electron Affinities of Halogen Diatomic Molecules as Determined by Endoergic Charge Exchange,
J. Chem. Phys., 1971, 55, 6, 2724, https://doi.org/10.1063/1.1676487
. [all data]
DeCorpo and Franklin, 1971
DeCorpo, J.J.; Franklin, J.L.,
Electron affinities of the halogen molecules by dissociative electron attachment,
J. Chem. Phys., 1971, 54, 1885. [all data]
Hubers, Kleyn, et al., 1976
Hubers, M.M.; Kleyn, A.W.; Los, J.,
Ion pair formation in alkali-halogen collisions at high velocities,
Chem. Phys., 1976, 17, 303. [all data]
Lacmann and Herschbach, 1970
Lacmann, K.; Herschbach, D.R.,
Collisional Excitation and Ionization of K Atoms by Diatomic Molecules: Role of Ion-pair States,
Chem. Phys. Lett., 1970, 6, 2, 106, https://doi.org/10.1016/0009-2614(70)80144-0
. [all data]
Yencha, Hopkirk, et al., 1995
Yencha, A.J.; Hopkirk, A.; Hiraya, A.; Donovan, R.J.; Goode, J.G.; Maier, R.R.J.; King, G.C.; Kvaran, A.,
Threshold photoelectron spectroscopy of Cl2 and Br2 up to 35 eV,
J. Phys. Chem., 1995, 99, 7231. [all data]
Van Lonkhuyzen and De Lange, 1984
Van Lonkhuyzen, H.; De Lange, C.A.,
High-resolution UV photoelectron spectroscopy of diatomic halogens,
Chem. Phys., 1984, 89, 313. [all data]
Huber and Herzberg, 1979
Huber, K.P.; Herzberg, G.,
Molecular Spectra and Molecular Structure. IV. Constants of Diatomic Molecules,, Van Nostrand Reinhold Co., 1979, ,1. [all data]
Potts and Price, 1971
Potts, A.W.; Price, W.C.,
Photoelectron spectra of the halogens and mixed halides ICI and lBr,
J. Chem. Soc. Faraday Trans., 1971, 67, 1242. [all data]
Dibeler, Walker, et al., 1971
Dibeler, V.H.; Walker, J.A.; McCulloh, K.E.; Rosenstock, H.M.,
Effect of hot bands on the ionization threshold of some diatomic halogen molecules,
Intern. J. Mass Spectrom. Ion Phys., 1971, 7, 209. [all data]
Cornford, Frost, et al., 1971
Cornford, A.B.; Frost, D.C.; McDowell, C.A.; Ragle, J.L.; Stenhouse, I.A.,
Photoelectron spectra of the halogens,
J. Chem. Phys., 1971, 54, 2651. [all data]
Anderson, Mamantov, et al., 1971
Anderson, C.P.; Mamantov, G.; Bull, W.E.; Grimm, F.A.; Carver, J.C.; Carlson, T.A.,
Photoelectron spectrum of chlorine monofluoride,
Chem. Phys. Lett., 1971, 12, 137. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Dyke, Josland, et al., 1984
Dyke, J.M.; Josland, G.D.; Snijders, J.G.; Boerrigter, P.M.,
Ionization energies of the diatomic halogens and interhalogens studied with relativistic hartree-fock-slater calculations,
Chem. Phys., 1984, 91, 419. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Frost and McDowell, 1959
Frost, D.C.; McDowell, C.A.,
Recent electron impact studies on simple molecules (O2, Cl2, I2),
Advan. Mass Spectrom., 1959, 1, 413. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity Pc Critical pressure Ptriple Triple point pressure S°gas,1 bar Entropy of gas at standard conditions (1 bar) Tboil Boiling point Tc Critical temperature Ttriple Triple point temperature ρc 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.