potassium iodide
- Formula: IK
- Molecular weight: 166.0028
- IUPAC Standard InChI: InChI=1S/HI.K/h1H;/q;+1/p-1
- IUPAC Standard InChIKey: NLKNQRATVPKPDG-UHFFFAOYSA-M
- CAS Registry Number: 7681-11-0
- Chemical structure:
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Gas 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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | -30.000 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1967 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°gas,1 bar | 61.730 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1967 |
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) | 2500. to 6000. |
|---|---|
| A | 8.940302 |
| B | 0.198002 |
| C | -0.000485 |
| D | 0.000042 |
| E | -0.011316 |
| F | -32.71231 |
| G | 72.42770 |
| H | -30.00000 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in June, 1967 |
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.
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°liquid | -74.773 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1967 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°liquid,1 bar | 27.271 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1967 |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔfH°solid | -78.370 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1967 |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid | 25.423 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1967 |
Liquid 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) | 954. to 2500. |
|---|---|
| A | 17.30000 |
| B | -3.890280×10-10 |
| C | 2.440010×10-10 |
| D | -4.843060×10-11 |
| E | -9.848151×10-12 |
| F | -79.93000 |
| G | 48.20590 |
| H | -74.77211 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in June, 1967 |
Solid 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 954. |
|---|---|
| A | 17.59650 |
| B | -20.41980 |
| C | 31.09400 |
| D | -11.67930 |
| E | -0.120080 |
| F | -83.36489 |
| G | 50.85120 |
| H | -78.37010 |
| Reference | Chase, 1998 |
| Comment | Data last reviewed in June, 1967 |
Phase change 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.
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 |
|---|---|---|---|---|---|
| 1018. to 1597. | 4.39650 | 6421.797 | -136.338 | Stull, 1947 | Coefficents calculated by NIST from author's data. |
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 compiled as indicated in comments:
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
B - John E. Bartmess
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.728 ± 0.010 | LPES | Miller, Leopold, et al., 1986 | B |
| 0.50 ± 0.10 | LPES | Yang, Bloomfield, et al., 1992 | EA given is Vertical Detachment Energy. Adiabatic EA est as up to 1 eV smaller; B |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 7.5 ± 0.4 | EI | Emons, Horlbeck, et al., 1982 | LBLHLM |
| 7.2 ± 0.1 | PE | Potts and Price, 1977 | LLK |
| 7.2 ± 0.1 | PE | Potts, Williams, et al., 1974 | LLK |
| 8.2 ± 0.3 | EI | Platel, 1965 | RDSH |
| 7.4 | PE | Goodman, Allen, et al., 1974 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| I+ | 14.6 ± 0.3 | K | EI | Platel, 1965 | RDSH |
| K+ | 8.6 ± 0.3 | I | EI | Platel, 1965 | RDSH |
| K+ | 25.14 ± 0.04 | I(-) | PE | Potts and Price, 1977 | Vertical value; LLK |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change 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]
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]
Miller, Leopold, et al., 1986
Miller, T.M.; Leopold, D.G.; Murray, K.K.; Lineberger, W.C.,
Electron Affinities of the Alkali Halides and the Structure of their Negative Ions,
J. Chem. Phys., 1986, 85, 5, 2368, https://doi.org/10.1063/1.451091
. [all data]
Yang, Bloomfield, et al., 1992
Yang, Y.A.; Bloomfield, L.A.; Jin, C.; Wang, L.S.; Smalley, R.E.,
Ultraviolet Photoelectron Spectroscopy and Photofragmentation Studies of Excess Electrons in Potassium Iodide Cluster Anions,
J. Chem. Phys., 1992, 96, 4, 2453, https://doi.org/10.1063/1.462049
. [all data]
Emons, Horlbeck, et al., 1982
Emons, H.-H.; Horlbeck, W.; Kiessling, D.,
Massenspektrometrische untersuchung der gasphase uber alkalimetalliodiden,
Z. Anorg. Allg. Chem., 1982, 488, 212. [all data]
Potts and Price, 1977
Potts, A.W.; Price, W.C.,
Photoelectron studies of ionic materials using molecular beam techniques,
Phys. Scr., 1977, 16, 191. [all data]
Potts, Williams, et al., 1974
Potts, A.W.; Williams, T.A.; Price, W.C.,
Photoelectron spectra and electronic structure of diatomic alkali halides,
Proc. Roy. Soc. London A, 1974, 341, 147. [all data]
Platel, 1965
Platel, G.,
Mesures des potentials d'apparition des ions obtenus par impact electronique dans la phase vapeur des iodures alcalins et des melanges LiI-MI,
J. Chim. Phys., 1965, 62, 1176. [all data]
Goodman, Allen, et al., 1974
Goodman, T.D.; Allen, J.D., Jr.; Cusachs, L.C.; Schweitzer, G.K.,
The photoelectron spectra of gaseous alkali halides,
J. Electron Spectrosc. Relat. Phenom., 1974, 3, 289. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity S°gas,1 bar Entropy of gas at standard conditions (1 bar) S°liquid,1 bar Entropy of liquid at standard conditions (1 bar) S°solid Entropy of solid at standard conditions ΔfH°gas Enthalpy of formation of gas at standard conditions 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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