calcium oxide

• Formula: CaO
• Molecular weight: 56.077
• IUPAC Standard InChI: InChI=1S/Ca.O Copy

  
• IUPAC Standard InChIKey: ODINCKMPIJJUCX-UHFFFAOYSA-N Copy
• CAS Registry Number: 1305-78-8
• Chemical structure:
  This structure is also available as a 2d Mol file
• Other names: Calcium monoxide
• Permanent link for this species. Use this link for bookmarking this species for future reference.
• Information on this page:
  • Condensed phase thermochemistry data
  • Gas phase ion energetics data
  • References
  • Notes
• Other data available:
  • Gas phase thermochemistry data
  • Constants of diatomic molecules
• Data at other public NIST sites:
  • Microwave spectra (on physics lab web site)
  • Gas Phase Kinetics Database
  • X-ray Photoelectron Spectroscopy Database, version 5.0
• Options:
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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.

Liquid 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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Solid 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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Gas phase ion energetics 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 evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
L - Sharon G. Lias

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

Ionization energy determinations

References

Go To: Top, Condensed phase 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.

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

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]

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]

Dalleska and Armentrout, 1994
Dalleska, N.F.; Armentrout, P.B., Guided ion beam studies of reactions of alkaline earth ions with O₂, Int. J. Mass Spectrom. Ion Processes, 1994, 134, 203. [all data]

Belyaev, Gotkis, et al., 1990
Belyaev, V.N.; Gotkis, I.S.; Lebedeva, N.L.; Krasnov, K.S., Ionization potentials of MX molecules (M = Ca, Sr, Ba; X = F, Cl, Br, I, OH, O), Russ. J. Phys. Chem., 1990, 64, 773. [all data]

Farber, Srivastava, et al., 1987
Farber, M.; Srivastava, R.D.; Moyer, J.W.; Leeper, J.D., Effusion mass spectrometric determination of thermodynamic properties of the gaseous mono- and di-hydroxides of calcium and KCaO(g), J. Chem. Soc. Faraday Trans. 2, 1987, 83, 3229. [all data]

Murad, 1983
Murad, E., Abstraction reactions of Ca⁺ and Sr⁺ ions, J. Chem. Phys., 1983, 78, 6611. [all data]

Farber and Srivastava, 1976
Farber, M.; Srivastava, R.D., The dissociation energies of calcium oxide and strontium oxide, High Temp. Sci., 1976, 8, 73. [all data]

Drowart, Exsteen, et al., 1964
Drowart, J.; Exsteen, G.; Verhaegen, G., Mass spectrometric determination of the dissociation energy of the molecules MgO, CaO, SrO and Sr₂O, J. Chem. Soc. Faraday Trans., 1964, 60, 1920. [all data]

Notes

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

• Symbols used in this document:
  

  IE (evaluated)	Recommended ionization energy
  S°liquid,1 bar	Entropy of liquid at standard conditions (1 bar)
  S°solid	Entropy of solid at standard conditions
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  ΔfH°liquid	Enthalpy of formation of liquid at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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