Iodine
- Formula: I2
- Molecular weight: 253.80894
- IUPAC Standard InChI: InChI=1S/I2/c1-2
- IUPAC Standard InChIKey: PNDPGZBMCMUPRI-UHFFFAOYSA-N
- CAS Registry Number: 7553-56-2
- 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: I2; Eranol; Iode; Iodine-127; Iodio; Iosan Superdip; Jod; Jood; Molecular iodine; Tincture iodine; Vistarin; Iodine crystals; Iodine sublimed; Diiodine; Diatomic iodine
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Gas phase thermochemistry data
Go To: Top, 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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | 14.92 ± 0.02 | kcal/mol | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
| ΔfH°gas | 14.92 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1982 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 62.306 ± 0.001 | cal/mol*K | Review | Cox, Wagman, et al., 1984 | CODATA Review value |
| S°gas,1 bar | 62.306 | cal/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 (cal/mol*K)
H° = standard enthalpy (kcal/mol)
S° = standard entropy (cal/mol*K)
t = temperature (K) / 1000.
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| Temperature (K) | 457.666 to 2000. | 2000. to 6000. |
|---|---|---|
| A | 9.033851 | 18.33990 |
| B | 0.053884 | -0.966965 |
| C | -0.218106 | -0.441717 |
| D | 0.247350 | 0.052353 |
| E | -0.020035 | -19.69260 |
| F | 12.15790 | -12.87560 |
| G | 73.11661 | 67.21479 |
| H | 14.91900 | 14.91900 |
| Reference | Chase, 1998 | Chase, 1998 |
| Comment | Data last reviewed in June, 1982 | Data last reviewed in June, 1982 |
Phase change data
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.
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
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| Temperature (K) | A | B | C | Reference | Comment |
|---|---|---|---|---|---|
| 311.9 to 456. | 3.35858 | 1039.159 | -146.589 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
References
Go To: Top, Gas phase thermochemistry data, Phase change 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]
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]
Notes
Go To: Top, Gas phase thermochemistry data, Phase change data, 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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