Benzene, chloro-

• Formula: C₆H₅Cl
• Molecular weight: 112.557
• IUPAC Standard InChI: InChI=1S/C6H5Cl/c7-6-4-2-1-3-5-6/h1-5H Copy

  
• IUPAC Standard InChIKey: MVPPADPHJFYWMZ-UHFFFAOYSA-N Copy
• CAS Registry Number: 108-90-7
• 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: Chlorobenzene; Monochlorobenzene; MCB; Phenyl Chloride; Benzene chloride; Chlorbenzene; Chlorobenzol; Monochlorbenzene; Chloorbenzeen; Chlorbenzol; Chlorobenzen; Chlorobenzene, mono-; Clorobenzene; Monochloorbenzeen; Monochlorbenzol; Monoclorobenzene; NCI-C54886; Chlorobenzenu; UN 1134; Abluton T30; CP 27; IP Carrier T 40; NSC 8433; Tetrosin SP
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Reaction thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Phase change data
  • Henry's Law data
  • Ion clustering data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • Gas Chromatography
• Data at other public NIST sites:
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
  • Switch to calorie-based units

Data at NIST subscription sites:

• 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, Condensed phase thermochemistry data, Reaction 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 by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Condensed phase thermochemistry data

Go To: Top, Gas phase thermochemistry data, Reaction 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of liquid

Constant pressure heat capacity of solid

Reaction thermochemistry data

Go To: Top, Gas phase thermochemistry data, Condensed 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:
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.

Individual Reactions

 +  = ( • )

By formula: Cl^- + C₆H₅Cl = (Cl^- • C₆H₅Cl)

Free energy of reaction

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

 +  = ( • )

By formula: Br^- + C₆H₅Cl = (Br^- • C₆H₅Cl)

Free energy of reaction

C₆H₇N⁺ +  = (C₆H₇N⁺ • )

By formula: C₆H₇N⁺ + C₆H₅Cl = (C₆H₇N⁺ • C₆H₅Cl)

Bond type: Charge transfer bond (positive ion)

Free energy of reaction

C₉H₁₂⁺ +  = (C₉H₁₂⁺ • )

By formula: C₉H₁₂⁺ + C₆H₅Cl = (C₉H₁₂⁺ • C₆H₅Cl)

Bond type: Charge transfer bond (positive ion)

Free energy of reaction

 +  = ( • )

By formula: NO^- + C₆H₅Cl = (NO^- • C₆H₅Cl)

 +  =  + 

By formula: C₆H₅Cl + C₁₂H₁₇Cl = C₉H₁₁Cl + C₉H₁₁Cl

 +  =  + 

By formula: C₆H₅Cl + C₁₄H₂₁Cl = C₁₀H₁₃Cl + C₁₀H₁₃Cl

 +  =  + 

By formula: C₉H₁₁Cl + C₆H₆ = C₆H₅Cl + C₉H₁₂

 +  = 2

By formula: C₆H₅Cl + C₁₄H₂₁Cl = 2C₁₀H₁₃Cl

 +  =  + 

By formula: C₆H₆ + Cl₂ = C₆H₅Cl + HCl

Gas phase ion energetics data

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

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

Data compiled as indicated in comments:
B - John E. Bartmess
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
LL - Sharon G. Lias and Joel F. Liebman

View reactions leading to C₆H₅Cl⁺ (ion structure unspecified)

Ionization energy determinations

Appearance energy determinations

De-protonation reactions

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

C₆H₄Cl^- +  =

By formula: C₆H₄Cl^- + H⁺ = C₆H₅Cl

References

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

Platonov and Simulin, 1985
Platonov, V.A.; Simulin, Yu.N., Determination of the standard enthalpies of formation of polychlorobenzenes. III. The standard enthalpies of formation of mono-1,2,4- and 1,3,5-tri-, and 1,2,3,4- and 1,2,3,5-tetrachlorobenzenes, Russ. J. Phys. Chem. (Engl. Transl.), 1985, 59, 179-181. [all data]

Kolesov, Tomareva, et al., 1967
Kolesov, V.P.; Tomareva, E.M.; Skuratov, S.M.; Alekhin, S.P., Calorimeter having a rotating bomb for determining heats of combustion of chlorinated organic compounds, Russ. J. Phys. Chem. (Engl. Transl.), 1967, 41, 817-820. [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]

Hubbard, Knowlton, et al., 1954
Hubbard, W.N.; Knowlton, J.W.; Huffman, H.M., Combustion calorimetry of organic chlorine compounds. Heats of combustion of chlorobenzene, the dichlorobenzenes and o- and p-chloroethylbenzene, J. Phys. Chem., 1954, 58, 396. [all data]

Smith, Bjellerup, et al., 1953
Smith, L.; Bjellerup, L.; Krook, S.; Westermark, H., Heats of combustion of organic chloro compounds determined by the "quartz wool" method, Acta Chem. Scand., 1953, 7, 65. [all data]

Stull, 1937
Stull, D.R., A semi-micro calorimeter for measuring heat capacities at low temperatures, J. Am. Chem. Soc., 1937, 59, 2726-2733. [all data]

Shehatta, 1993
Shehatta, I., Heat capacity at constant pressure of some halogen compounds, Thermochim. Acta, 1993, 213, 1-10. [all data]

Perez-Casas, Aicart, et al., 1988
Perez-Casas, S.; Aicart, E.; Trojo, L.M.; Costas, M., Excess heat capacity. Chlorobenzene-2,2,4,4,6,8,8-heptamethylnonane, Int. Data Ser., Sel. Data Mixtures, 1988, (2)A, 123. [all data]

Reddy, 1986
Reddy, K.S., Isentropic compressibilities of binary liquid mixtures at 303.15 and 313.15 K, J. Chem. Eng. Data, 1986, 31, 238-240. [all data]

Fortier and Benson, 1977
Fortier, J.-L.; Benson, G.C., Excess heat capacities of binary mixtures of tetrachloromethane witlh some aromatic liquids at 298.15 K, J. Chem. Thermodynam., 1977, 9, 1181-1188. [all data]

Deshpande and Bhatagadde, 1971
Deshpande, D.D.; Bhatagadde, L.G., Heat capacities at constant volume, free volumes, and rotational freedom in some liquids, Aust. J. Chem., 1971, 24, 1817-1822. [all data]

Phillip, 1939
Phillip, N.M., Adiabatic and isothermal compressibilities of liquids, Proc. Indian Acad. Sci., 1939, A9, 109-120. [all data]

Williams and Daniels, 1925
Williams, J.W.; Daniels, F., The specific heats of binary mixtures, J. Am. Chem. Soc., 1925, 47, 1490-1503. [all data]

von Reis, 1881
von Reis, M.A., Die specifische Wärme flüssiger organischer Verbindungen und ihre Beziehung zu deren Moleculargewicht, Ann. Physik [3], 1881, 13, 447-464. [all data]

Andrews and Haworth, 1928
Andrews, D.H.; Haworth, E., An application of the rule of Dulong and Petit to molecules, J. Am. Chem. Soc., 1928, 50, 2998-3002. [all data]

Sieck, 1985
Sieck, L.W., Thermochemistry of Solvation of NO₂^- and C₆H₅NO₂^- by Polar Molecules in the Vapor Phase. Comparison with Cl^- and Variation with Ligand Structure., J. Phys. Chem., 1985, 89, 25, 5552, https://doi.org/10.1021/j100271a049 . [all data]

Larson and McMahon, 1984
Larson, J.W.; McMahon, T.B., Gas phase negative ion chemistry of alkylchloroformates, Can. J. Chem., 1984, 62, 675. [all data]

Paul and Kebarle, 1991
Paul, G.J.C.; Kebarle, P., Stabilities of Complexes of Br- with Substituted Benzenes (SB) Based on Determinations of the Gas-Phase Equilibria Br- + SB = (BrSB)-, J. Am. Chem. Soc., 1991, 113, 4, 1148, https://doi.org/10.1021/ja00004a014 . [all data]

French, Ikuta, et al., 1982
French, M.A.; Ikuta, S.; Kebarle, P., Hydrogen bonding of O-H and C-H hydrogen donors to Cl^-. Results from mass spectrometric measurement of the ion-molecule equilibria RH + Cl^- = RHCl^-, Can. J. Chem., 1982, 60, 1907. [all data]

Wenthold and Squires, 1995
Wenthold, P.G.; Squires, R.R., Determination of the gas-phase acidities of halogen-substituted aromatic compounds using the silane-cleavage method, J. Mass Spectrom., 1995, 30, 1, 17, https://doi.org/10.1002/jms.1190300105 . [all data]

Wenthold and Squires, 1994
Wenthold, P.G.; Squires, R.R., Gas-phase properties and reactivity of the acetate radical anion. Determination of the C-H bond strengths in acetic acid and acetate ion, J. Am. Chem. Soc., 1994, 116, 26, 11890, https://doi.org/10.1021/ja00105a032 . [all data]

Wenthold, Paulino, et al., 1991
Wenthold, P.G.; Paulino, J.A.; Squires, R.R., The Absolute Heats of Formation of ortho-Benzyne, meta-Benzyne, and para-Benzyne, J. Am. Chem. Soc., 1991, 113, 19, 7414, https://doi.org/10.1021/ja00019a044 . [all data]

Andrade and Riveros, 1996
Andrade, P.B.M.; Riveros, J.M., Relative Gas-phase Acidities of Fluoro- and Chlorobenzene, J. Mass Spectrom., 1996, 31, 7, 767, https://doi.org/10.1002/(SICI)1096-9888(199607)31:7<767::AID-JMS345>3.0.CO;2-Q . [all data]

Bartmess and McIver Jr., 1979
Bartmess, J.E.; McIver Jr., The Gas Phase Acidity Scale in Gas Phase Ion Chemistry, Gas Phase Ion Chemistry, V. 2, M.T. Bowers, Ed., Academic Press, NY, 1979, Ch. 11, Elsevier, 1979. [all data]

Meot-Ner (Mautner) and El-Shall, 1986
Meot-Ner (Mautner), M.; El-Shall, M.S., Ionic Charge Transfer Complexes. 1. Cationic Complexes with Delocalized and Partially Localized pi Systems, J. Am. Chem. Soc., 1986, 108, 15, 4386, https://doi.org/10.1021/ja00275a026 . [all data]

Meot-Ner (Mautner), Hamlet, et al., 1978
Meot-Ner (Mautner), M.; Hamlet, P.; Hunter, E.P.; Field, F.H., Bonding Energies in Association Ions of Aromatic Molecules. Correlations with Ionization Energies, J. Am. Chem. Soc., 1978, 100, 17, 5466, https://doi.org/10.1021/ja00485a034 . [all data]

Reents and Freiser, 1981
Reents, W.D.; Freiser, B.S., Gas-Phase Binding Energies and Spectroscopic Properties of NO+ Charge-Transfer Complexes, J. Am. Chem. Soc., 1981, 103, 2791. [all data]

Farid and McMahon, 1978
Farid, R.; McMahon, T.B., Gas-Phase Ion-Molecule Reactions of Alkyl Nitrites by Ion Cyclotron Resonance Spectroscopy, Int. J. Mass Spectrom. Ion Phys., 1978, 27, 2, 163, https://doi.org/10.1016/0020-7381(78)80037-0 . [all data]

Nesterova, Rozhnov, et al., 1985
Nesterova, T.N.; Rozhnov, A.M.; Malova, T.N.; Kovzel, E.N., Molar enthalpies of formation of isopropylchlorobenzenes derived from equilibrium measurements, J. Chem. Thermodyn., 1985, 17, 649-656. [all data]

Kovzel, Nesterova, et al., 1981
Kovzel, E.N.; Nesterova, T.N.; Rozhnov, A.M.; Kartavtseva, T.A., Study of equilibrium in in the chlorobenzene-butylchlorobenzenes systems, Termodin. Organ. Soedin., 1981, 65-68. [all data]

Kirkbride, 1956
Kirkbride, F.W., The heats of chlorination of some hydrocarbons and their chloro-derivatives, J. Appl. Chem., 1956, 6, 11-21. [all data]

Hunter and Lias, 1998
Hunter, E.P.; Lias, S.G., Evaluated Gas Phase Basicities and Proton Affinities of Molecules: An Update, J. Phys. Chem. Ref. Data, 1998, 27, 3, 413-656, https://doi.org/10.1063/1.556018 . [all data]

Fujisawa, Ohno, et al., 1986
Fujisawa, S.; Ohno, K.; Masuda, S.; Harada, Y., Penning ionization electron spectroscopy of monohalogenobenzenes: C₆H₅F, C₆H₅Cl, C₆H₅Br, and C₆H₅I, J. Am. Chem. Soc., 1986, 108, 6505. [all data]

Klasinc, Kovac, et al., 1983
Klasinc, L.; Kovac, B.; Gusten, H., Photoelectron spectra of acenes. Electronic structure and substituent effects, Pure Appl. Chem., 1983, 55, 289. [all data]

Ruscic, Klasinc, et al., 1981
Ruscic, B.; Klasinc, L.; Wolf, A.; Knop, J.V., Photoelectron spectra of and Ab initio calculations on chlorobenzenes. 1. Chlorobenzene and dichlorobenzenes, J. Phys. Chem., 1981, 85, 1486. [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]

Mohraz, Maier, et al., 1980
Mohraz, M.; Maier, J.P.; Heilbronner, E., He(I α) and He(Iα) photoelectron spectra of fluorinated chloro- and bromobenzenes, J. Electron Spectrosc. Relat. Phenom., 1980, 19, 429. [all data]

Maier and Marthaler, 1978
Maier, J.P.; Marthaler, O., Emission spectra of the radical cations of 1,3-dichlorobenzene, 1,4-dichlorobenzene and 1,3,5-trichlorobenzene in the gas phase, Chem. Phys., 1978, 32, 419. [all data]

Lias and Ausloos, 1978
Lias, S.G.; Ausloos, P.J., eIonization energies of organic compounds by equilibrium measurements, J. Am. Chem. Soc., 1978, 100, 6027. [all data]

Behan, Johnstone, et al., 1976
Behan, J.M.; Johnstone, R.A.W.; Bentley, T.W., An evaluation of empirical methods for calculating the ionization potentials of substituted benzenes, Org. Mass Spectrom., 1976, 11, 207. [all data]

Baldwin, Loudon, et al., 1976
Baldwin, M.A.; Loudon, A.G.; Maccoll, A.; Webb, K.S., The nature and fragmentation pathways of the molecular ions of some arylureas, arylthioureas, acetanilides, thioacetanilides and related compounds, Org. Mass Spectrom., 1976, 11, 1181. [all data]

Baer, Tsai, et al., 1976
Baer, T.; Tsai, B.P.; Smith, D.; Murray, P.T., Absolute unimolecular decay rates of energy selected metastable halobenzene ions, J. Chem. Phys., 1976, 64, 2460. [all data]

Gilbert, Leach, et al., 1973
Gilbert, J.R.; Leach, W.P.; Miller, J.R., Ionisation appearance potential measurements in arene chromium tricarbonyls, J. Organomet. Chem., 1973, 49, 219. [all data]

Cooks, Bertrand, et al., 1973
Cooks, R.G.; Bertrand, M.; Beynon, J.H.; Rennekamp, M.E.; Setser, D.W., Energy partitioning data as an ion structure probe. Substituted anisoles, J. Am. Chem. Soc., 1973, 95, 1732. [all data]

Sergeev, Akopyan, et al., 1970
Sergeev, Yu.L.; Akopyan, M.E.; Vilesov, F.I.; Kleimenov, V.I., Photoionization processes in phenyl halides, Opt. i Spektroskopiya, 1970, 29, 119, In original 63. [all data]

Momigny, Goffart, et al., 1968
Momigny, J.; Goffart, C.; D'Or, L., Photoionization studies by total ionization measurements. I. Benzene and its monohalogeno derivatives, Intern. J. Mass Spectrom. Ion Phys., 1968, 1, 53. [all data]

Quemerais, Morlais, et al., 1967
Quemerais, A.; Morlais, M.; Robin, S., Spectres d'absorption du benzene et du monochlorobenzene dans l'ultraviolet de 1300 a 2300 A, Compt. Rend., 1967, 265, 649. [all data]

Bralsford, Harris, et al., 1960
Bralsford, R.; Harris, P.V.; Price, W.C., The effect of fluorine on the electronic spectra and ionization potentials of molecules, Proc. Roy. Soc. (London), 1960, A258, 459. [all data]

Watanabe, 1957
Watanabe, K., Ionization potentials of some molecules, J. Chem. Phys., 1957, 26, 542. [all data]

Potts, Lyus, et al., 1980
Potts, A.W.; Lyus, M.L.; Lee, E.P.F.; Fattahallah, G.H., High resolution ultraviolet photoelectron spectra of C₆H₅X and p-C₆H₄X₂ where X = Cl, Br or I, J. Chem. Soc. Faraday Trans. 2, 1980, 76, 556. [all data]

Sell and Kupperman, 1978
Sell, J.A.; Kupperman, A., Angular distributions in the photoelectron spectra of benzene and its monohalogenated derivatives, Chem. Phys., 1978, 33, 367. [all data]

Klasinc, Novak, et al., 1978
Klasinc, L.; Novak, I.; Scholz, M.; Kluge, G., Photoelektronenspektren substituierter Pyridine und Benzole und ihre Interpretation durch die CNDO/SWW-Methode, Croat. Chem. Acta, 1978, 51, 43. [all data]

Streets and Ceasar, 1973
Streets, D.G.; Ceasar, G.P., Inductive mesomeric effects on the π orbitals of halobenzenes, Mol. Phys., 1973, 26, 1037. [all data]

Momigny, 1959
Momigny, J., Determination et discussion des potentials d'apparition d'ions fragmentaires dans le benzene et ses derives monohalogenes, Bull. Soc. Roy. Sci. Liege, 1959, 28, 251. [all data]

Ripoche, Dimicoli, et al., 1991
Ripoche, X.; Dimicoli, I.; Botter, R., Unimolecular decay rates for laser induced Cl loss from energy selected chlorobenzene cations [E_o(C₆H₅Cl⁺ Ü C₆H₅⁺ + Cl)=2.74±0.02 eV; cited data derived using recommended IP for chlorobenzene.], Int. J. Mass Spectrom. Ion Processes, 1991, 107, 165. [all data]

Burgers and Holmes, 1984
Burgers, P.C.; Holmes, J.L., Fragmentation rate constants and appearance energies for reactions having a large kinetic shift and the energy partitioning in their metastable decomposition, Int. J. Mass Spectrom. Ion Processes, 1984, 58, 15. [all data]

Rosenstock, Stockbauer, et al., 1980
Rosenstock, H.M.; Stockbauer, R.; Parr, A.C., Photoelectron-photoion coincidence study of the bromobenzene ion, J. Chem. Phys., 1980, 73, 773. [all data]

Rosenstock, Stockbauer, et al., 1979
Rosenstock, H.M.; Stockbauer, R.; Parr, A.C., Kinetic shift in chlorobenzene ion fragmentation and the heat of formation of the phenyl ion, J. Chem. Phys., 1979, 71, 3708. [all data]

Johnstone and Mellon, 1972
Johnstone, R.A.W.; Mellon, F.A., Electron-impact ionization and appearance potentials, J. Chem. Soc. Faraday Trans. 2, 1972, 68, 1209. [all data]

Majer and Patrick, 1962
Majer, J.R.; Patrick, C.R., Electron impact on some halogenated aromatic compounds, J. Chem. Soc. Faraday Trans., 1962, 58, 17. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, Gas phase ion energetics data, References

• Symbols used in this document:
  

  AE	Appearance energy
  Cp,liquid	Constant pressure heat capacity of liquid
  Cp,solid	Constant pressure heat capacity of solid
  IE (evaluated)	Recommended ionization energy
  S°liquid	Entropy of liquid at standard conditions
  T	Temperature
  ΔcH°liquid	Enthalpy of combustion of liquid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔrS°	Entropy of reaction at standard conditions

• 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.