Hydrogen iodide
- Formula: HI
- Molecular weight: 127.91241
- IUPAC Standard InChI: InChI=1S/HI/h1H
- IUPAC Standard InChIKey: XMBWDFGMSWQBCA-UHFFFAOYSA-N
- CAS Registry Number: 10034-85-2
- Chemical structure:
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Gas phase thermochemistry data
Go To: Top, 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 | 6.334 ± 0.024 | kcal/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
| ΔfH°gas | 6.300 | kcal/mol | Review | Chase, 1998 | Data last reviewed in September, 1961 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 49.376 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in September, 1961 |
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) | 298. to 1400. | 1400. to 6000. |
|---|---|---|
| A | 6.225000 | 8.471219 |
| B | 1.120860 | 0.338123 |
| C | 1.173941 | -0.043520 |
| D | -0.634416 | 0.002813 |
| E | 0.029020 | -0.969063 |
| F | 4.482551 | 1.892711 |
| G | 56.69259 | 57.38760 |
| H | 6.299960 | 6.299960 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in September, 1961 | Data last reviewed in September, 1961 |
References
Go To: Top, Gas phase thermochemistry 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]
Notes
Go To: Top, Gas phase thermochemistry data, References
- Symbols used in this document:
S°gas Entropy of gas at standard conditions 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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