Calcium
- Formula: Ca2
- Molecular weight: 80.156
- IUPAC Standard InChI: InChI=1S/2Ca
- IUPAC Standard InChIKey: CPGKMLVTFNUAHL-UHFFFAOYSA-N
- CAS Registry Number: 12595-85-6
- Chemical structure:
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Gas phase thermochemistry data
Go To: Top, Constants of diatomic molecules, 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 |
|---|---|---|---|---|---|
| ΔfH°gas | 341.64 | kJ/mol | Review | Chase, 1998 | Data last reviewed in September, 1983 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 257.19 | J/mol*K | Review | Chase, 1998 | Data last reviewed in September, 1983 |
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.
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| Temperature (K) | 298. to 1000. | 1000. to 6000. |
|---|---|---|
| A | 60.38432 | 22.76063 |
| B | -109.7292 | -1.526408 |
| C | 113.0785 | 0.318948 |
| D | -40.89262 | -0.002997 |
| E | -0.003522 | 1.250912 |
| F | 327.5834 | 339.7186 |
| G | 358.2964 | 293.4662 |
| H | 341.6374 | 341.6374 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in September, 1983 | Data last reviewed in September, 1983 |
Constants of diatomic molecules
Go To: Top, Gas phase 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 compiled by: Klaus P. Huber and Gerhard H. Herzberg
Data collected through July, 1976
| Symbol | Meaning |
|---|---|
| State | electronic state and / or symmetry symbol |
| Te | minimum electronic energy (cm-1) |
| ωe | vibrational constant – first term (cm-1) |
| ωexe | vibrational constant – second term (cm-1) |
| ωeye | vibrational constant – third term (cm-1) |
| Be | rotational constant in equilibrium position (cm-1) |
| αe | rotational constant – first term (cm-1) |
| γe | rotation-vibration interaction constant (cm-1) |
| De | centrifugal distortion constant (cm-1) |
| βe | rotational constant – first term, centrifugal force (cm-1) |
| re | internuclear distance (Å) |
| Trans. | observed transition(s) corresponding to electronic state |
| ν00 | position of 0-0 band (units noted in table) |
| State | Te | ωe | ωexe | ωeye | Be | αe | γe | De | βe | re | Trans. | ν00 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| A band system in the region 16100 - 16900 cm-1 and assigned to Ca2 by Kovalenok and Sokolov, 1967 is in all probability the same as that usually ascribed to CaO. 1 | ||||||||||||
| Emission continuum from 19500 to 25000 cm-1. | ||||||||||||
| ↳Hamada, 1931 | ||||||||||||
| A 1Σu+ | ≤18963.7 | ≥136.66 2 Z | 0.7166 3 | ≥0.058247 2 | 0.0003104 4 | 4.59E-08 5 | ≤3.8058 | A ← X 6 V | 18999.7 7 Z | |||
| ↳Weniger, 1966; missing citation | ||||||||||||
| X 1Σg+ | 0 | 64.928 Z | 1.0651 | 0.00259 | 0.046113 | 0.0007028 | -7.35E-06 | 9.52E-08 8 | 4.2773 | |||
Notes
| 1 | The Bv values quoted by Kovalenok and Sokolov, 1967 are of the same order as those for CaO. |
| 2 | Vibrational numbering unknown. |
| 3 | ωexe= -0.00374(v+1/2)3 - 0.000080(v+1/2)4. |
| 4 | αv= -[2.15(v+1/2)2 + 0.097[v+1/2)3]E-6. |
| 5 | He= 1.9kE-14. |
| 6 | RKR curves and Franck-Condon factors Balfour and Whitlock, 1975. |
| 7 | Energy of the lowest observed vibrational level relative to X 1Σg+ (v=0). |
| 8 | Dv= +[0.0431(v+1/2)+0.00107(v+1/2)2]E-7; He = -1.4E-13 Balfour and Whitlock, 1975 and higher order constants Balfour and Whitlock, 1975. |
| 9 | Extrapolation of the vibrational levels in X 1Σg+. |
References
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, 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]
Kovalenok and Sokolov, 1967
Kovalenok, G.V.; Sokolov, V.A.,
Quantum vibration analysis of the orange band of Ca2,
Izv. Sib. Otd. Akad. Nauk SSSR, Ser. Khim. Nauk, 1967, 4, 118. [all data]
Hamada, 1931
Hamada, H.,
III. On the molecular spectra of mercury, zinc, cadmium, magnesium, and thallium,
Philos. Mag., 1931, 12, 50. [all data]
Weniger, 1966
Weniger, S.,
L'elargissement de la raie 4226,73 Å(432 λSo-4P1 1P1o) de ca i dans les spectres de laboratoire et dans les etoiles d M
in Proceedings IAU Colloquim on Late-Type Stars, Trieste, M. Hack, ed(s)., 1966, 25-34. [all data]
Balfour and Whitlock, 1975
Balfour, W.J.; Whitlock, R.F.,
The visible absorption spectrum of diatomic calcium,
Can. J. Phys., 1975, 53, 472. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Constants of diatomic molecules, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) ΔfH°gas Enthalpy of formation of gas at standard conditions - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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