Nitric acid
- Formula: HNO3
- Molecular weight: 63.0128
- IUPAC Standard InChI: InChI=1S/HNO3/c2-1(3)4/h(H,2,3,4)
- IUPAC Standard InChIKey: GRYLNZFGIOXLOG-UHFFFAOYSA-N
- CAS Registry Number: 7697-37-2
- 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. - Permanent link for this species. Use this link for bookmarking this species for future reference.
- Information on this page:
- Other data available:
- Data at other public NIST sites:
- Options:
Data at NIST subscription sites:
NIST subscription sites provide data under the NIST Standard Reference Data Program, but require an annual fee to access. The purpose of the fee is to recover costs associated with the development of data collections included in such sites. Your institution may already be a subscriber. Follow the links above to find out more about the data in these sites and their terms of usage.
Phase change data
Go To: Top, Gas phase ion energetics 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: William E. Acree, Jr., James S. Chickos
Enthalpy of vaporization
| ΔvapH (kJ/mol) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 38.6 | 312. | Holeci, 1966 | Based on data from 273. to 356. K. |
Gas phase ion energetics 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.
Data evaluated as indicated in comments:
HL - Edward P. Hunter and Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LLK - Sharon G. Lias, Rhoda D. Levin, and Sherif A. Kafafi
RDSH - Henry M. Rosenstock, Keith Draxl, Bruce W. Steiner, and John T. Herron
LL - Sharon G. Lias and Joel F. Liebman
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| Proton affinity (review) | 751.4 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
| Quantity | Value | Units | Method | Reference | Comment |
| Gas basicity | 731.5 | kJ/mol | N/A | Hunter and Lias, 1998 | HL |
Electron affinity determinations
| EA (eV) | Method | Reference | Comment |
|---|---|---|---|
| 0.57 ± 0.15 | NBIE | Mathur, Rothe, et al., 1976 | B |
| 0.56 ± 0.17 | Endo | Paulson and Dale, 1982 | B |
Proton affinity at 298K
| Proton affinity (kJ/mol) | Reference | Comment |
|---|---|---|
| 670.3 | Bernardi, Cacace, et al., 1998 | PA at NO+ binding site, estimated from correlation of PAs with NO+ binding energies; MM |
Ionization energy determinations
| IE (eV) | Method | Reference | Comment |
|---|---|---|---|
| 11.95 ± 0.01 | PE | Lloyd, Roberts, et al., 1975 | LLK |
| 11.96 | PE | Frost, Lee, et al., 1975 | LLK |
| 11.03 ± 0.01 | PI | Nicholson, 1965 | RDSH |
| 12.2 | PE | Ames and Turner, 1976 | Vertical value; LLK |
Appearance energy determinations
| Ion | AE (eV) | Other Products | Method | Reference | Comment |
|---|---|---|---|---|---|
| OH+ | 16.6 | NO2 | PI | Jochims, Denzer, et al., 1992 | LL |
| NO+ | 13.07 | ? | PI | Jochims, Denzer, et al., 1992 | LL |
| NO2+ | 11.90 | OH | PI | Jochims, Denzer, et al., 1992 | LL |
De-protonation reactions
+
=
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1357.7 ± 0.84 | kJ/mol | TDEq | Davidson, Fehsenfeld, et al., 1977 | gas phase; Relative to HBr, reevaluated with current HBr acidity. Excited state at 3.0 eV,81WU /TIE.; B |
| ΔrH° | 1380. ± 20. | kJ/mol | NBAE | Mathur, Rothe, et al., 1976 | gas phase; From HNO3; B |
| ΔrH° | 1377. ± 24. | kJ/mol | Endo | Refaey and Franklin, 1976 | gas phase; I- + HNO3 ->.; B |
| ΔrH° | 1357.7 ± 2.1 | kJ/mol | TDEq | Ferguson, Dunkin, et al., 1972 | gas phase; B |
| ΔrH° | 1490.8 | kJ/mol | Endo | Berkowitz, Chupka, et al., 1971 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1329.7 ± 0.84 | kJ/mol | TDEq | Davidson, Fehsenfeld, et al., 1977 | gas phase; Relative to HBr, reevaluated with current HBr acidity. Excited state at 3.0 eV,81WU /TIE.; B |
References
Go To: Top, 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.
Holeci, 1966
Holeci, I.,
Chem. Prum., 1966, 16, 5, 267. [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]
Mathur, Rothe, et al., 1976
Mathur, B.P.; Rothe, E.W.; Tang, S.Y.; Mahajan, K.; Reck, G.P.,
Negative gaseous ions from nitric acid,
J. Chem. Phys., 1976, 64, 1247. [all data]
Paulson and Dale, 1982
Paulson, J.F.; Dale, J.,
Reactions of OH-.H2O with NO2,
J. Chem. Phys., 1982, 77, 4006. [all data]
Bernardi, Cacace, et al., 1998
Bernardi, F.; Cacace, F.; de Petris, G.; Pepi, F.; Rossi, I.,
Gaseous [N2O5]H+, [N2O4]H+, and related species from the addition of NO2+ and NO+ ions to nitric acid and its derivatives,
J. Phys. Chem. A, 1998, 102, 1987. [all data]
Lloyd, Roberts, et al., 1975
Lloyd, D.R.; Roberts, P.J.; Hillier, I.H.,
Electronic structure of nitric acid studied by photoelectron spectroscopy and molecular orbital calculation,
J. Chem. Soc. Faraday Trans. 2, 1975, 71, 496. [all data]
Frost, Lee, et al., 1975
Frost, D.C.; Lee, S.T.; McDowell, C.A.; Westwood, N.P.C.,
Photoelectron spectroscopic studies of some nitrosyl and nitryl halides nitric acid,
J. Electron Spectrosc. Relat. Phenom., 1975, 7, 331. [all data]
Nicholson, 1965
Nicholson, A.J.C.,
Photoionization-efficiency curves. II. False and genuine structure,
J. Chem. Phys., 1965, 43, 1171. [all data]
Ames and Turner, 1976
Ames, D.L.; Turner, D.W.,
Photoelectron spectroscopic studies of dinitrogen tetroxide and dinitrogen pentoxide,
Proc. R. Soc. London A:, 1976, 348, 175. [all data]
Jochims, Denzer, et al., 1992
Jochims, H.-W.; Denzer, W.; Baumgartel, H.; Losking, O.; Willner, H.,
Photochemical decay reactions of N2O5, HNO3, ClNO3 and BrNO3 in the energy range 10-20 eV,
Ber. Bunsen-Ges. Phys. Chem., 1992, 96, 573. [all data]
Davidson, Fehsenfeld, et al., 1977
Davidson, J.A.; Fehsenfeld, F.C.; Howard, C.J.,
The heats of formation of NO3- and NO3- association complexes with HNO3 and HBr,
Int. J. Chem. Kinet., 1977, 9, 17. [all data]
Refaey and Franklin, 1976
Refaey, K.M.A.; Franklin, J.L.,
Endoergic ion-molecule-collision processes of negative ions. V. Collision of I- on HNO3. The electron affinity of NO3,
J. Chem. Phys., 1976, 64, 4810. [all data]
Ferguson, Dunkin, et al., 1972
Ferguson, E.E.; Dunkin, D.B.; Fehsenfeld, F.C.,
Reactions of NO2- and NO3- with HCl and HBr,
J. Chem. Phys., 1972, 57, 1459. [all data]
Berkowitz, Chupka, et al., 1971
Berkowitz, J.; Chupka, W.A.; Gutman, D.,
Electron Affinities of O2, O3, NO, NO2, and NO3 by Endothermic Charge Transfer,
J. Chem. Phys., 1971, 55, 6, 2733, https://doi.org/10.1063/1.1676488
. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy EA Electron affinity ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions ΔvapH Enthalpy of vaporization - Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
- The National Institute of Standards and Technology (NIST) uses its best efforts to deliver a high quality copy of the Database and to verify that the data contained therein have been selected on the basis of sound scientific judgment. However, NIST makes no warranties to that effect, and NIST shall not be liable for any damage that may result from errors or omissions in the Database.
- Customer support for NIST Standard Reference Data products.