Nitrous acid
- Formula: HNO2
- Molecular weight: 47.0134
- IUPAC Standard InChIKey: IOVCWXUNBOPUCH-UHFFFAOYSA-N
- CAS Registry Number: 7782-77-6
- 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: HNO2; Kyselina dusite; Nitrosyl hydroxide; Nitrous acid, trans; HONO
- 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:
Gas phase thermochemistry data
Go To: Top, Henry's Law data, 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.
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔfH°gas | -18.34 | kcal/mol | Review | Chase, 1998 | Data last reviewed in June, 1963 |
Quantity | Value | Units | Method | Reference | Comment |
S°gas,1 bar | 59.610 | cal/mol*K | Review | Chase, 1998 | Data last reviewed in June, 1963 |
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.
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | 298. to 1200. | 1200. to 6000. | 298. to 2000. | 2000. to 6000. |
---|---|---|---|---|
A | 5.951181 | 17.60310 | 9.032075 | 18.90629 |
B | 21.83930 | 1.160370 | 12.96085 | 0.398523 |
C | -15.49860 | -0.220222 | -6.513241 | -0.062965 |
D | 4.283000 | 0.014541 | 1.219166 | 0.003561 |
E | -0.032203 | -2.177771 | -0.121963 | -3.596559 |
F | -21.06500 | -28.53480 | -22.46453 | -31.16109 |
G | 60.77130 | 74.17400 | 66.22753 | 74.41635 |
H | -18.34010 | -18.34010 | -18.84001 | -18.84001 |
Reference | Chase, 1998 | Chase, 1998 | Chase, 1998 | Chase, 1998 |
Comment | Data last reviewed in June, 1963 | Data last reviewed in June, 1963 | Data last reviewed in June, 1963 | Data last reviewed in June, 1963 |
Henry's Law data
Go To: Top, Gas phase thermochemistry data, 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: Rolf Sander
Henry's Law constant (water solution)
kH(T) = k°H exp(d(ln(kH))/d(1/T) ((1/T) - 1/(298.15 K)))
k°H = Henry's law constant for solubility in water at 298.15 K (mol/(kg*bar))
d(ln(kH))/d(1/T) = Temperature dependence constant (K)
k°H (mol/(kg*bar)) | d(ln(kH))/d(1/T) (K) | Method | Reference |
---|---|---|---|
50. | 4900. | M | Becker, Kleffmann, et al., 1996 |
49. | 4900. | M | N/A |
49. | 4800. | T | N/A |
48. | 4700. | T | N/A |
37. | C | N/A | |
49. | 4800. | L | N/A |
Gas phase ion energetics data
Go To: Top, Gas phase thermochemistry data, Henry's Law 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 as indicated in comments:
B - John E. Bartmess
LL - Sharon G. Lias and Joel F. Liebman
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
≤11.3 | DER | Lias, Bartmess, et al., 1988 | LL |
De-protonation reactions
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 340.23 ± 0.21 | kcal/mol | D-EA | Ervin, Ho, et al., 1988 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 333.73 ± 0.31 | kcal/mol | H-TS | Ervin, Ho, et al., 1988 | gas phase; B |
References
Go To: Top, Gas phase thermochemistry data, Henry's Law 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]
Becker, Kleffmann, et al., 1996
Becker, K.H.; Kleffmann, J.; Kurtenbach, R.; Wiesen, P.,
Solubility of Nitrous Acid (HONO) in Sulfuric Acid Solutions,
J. Phys. Chem., 1996, 100, 14984-14990. [all data]
Lias, Bartmess, et al., 1988
Lias, S.G.; Bartmess, J.E.; Liebman, J.F.; Holmes, J.L.; Levin, R.D.; Mallard, W.G.,
Gas-phase ion and neutral thermochemistry,
J. Phys. Chem. Ref. Data, Suppl. 1, 1988, 17, 1-861. [all data]
Ervin, Ho, et al., 1988
Ervin, K.M.; Ho, J.; Lineberger, W.C.,
Ultraviolet Photoelectron Spectrum of NO2-,
J. Phys. Chem., 1988, 92, 19, 5405, https://doi.org/10.1021/j100330a017
. [all data]
Notes
Go To: Top, Gas phase thermochemistry data, Henry's Law data, Gas phase ion energetics data, References
- Symbols used in this document:
S°gas,1 bar Entropy of gas at standard conditions (1 bar) d(ln(kH))/d(1/T) Temperature dependence parameter for Henry's Law constant k°H Henry's Law constant at 298.15K ΔfH°gas Enthalpy of formation of gas at standard conditions ΔrG° Free energy of reaction at standard conditions ΔrH° Enthalpy of reaction at standard conditions - 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.