Formaldehyde
- Formula: CH2O
- Molecular weight: 30.0260
- IUPAC Standard InChIKey: WSFSSNUMVMOOMR-UHFFFAOYSA-N
- CAS Registry Number: 50-00-0
- 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. - Isotopologues:
- Other names: Methanal; BFV; Fannoform; Formaldehyde, gas; Formalin; Formalith; Formic aldehyde; Formol; Fyde; Lysoform; Methyl aldehyde; Methylene oxide; Morbicid; Oxomethane; Oxymethylene; Paraform; Superlysoform; Karsan; Methaldehyde; Aldehyde formique; Aldeide formica; Formaldehyd; Formalin-loesungen; Formalina; Formaline; NCI-C02799; Oplossingen; Aldehyd mravenci; Formalin 40; Rcra waste number U122; UN 1198; UN 2209; H2CO; Durine; Hercules 37M6-8; CH2O; NSC 298885; Fordor
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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 as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
Tboil | 253.85 | K | N/A | Spence and Wild, 1935 | Uncertainty assigned by TRC = 0.2 K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Tfus | 181. | K | N/A | Anonymous, 1958 | Uncertainty assigned by TRC = 4. K; TRC |
Tfus | 181. | K | N/A | Harries, 1901 | Uncertainty assigned by TRC = 6. K; TRC |
Quantity | Value | Units | Method | Reference | Comment |
Ttriple | 155.1 | K | N/A | Spence and Wild, 1935 | Uncertainty assigned by TRC = 0.3 K; TRC |
Enthalpy of vaporization
ΔvapH (kcal/mol) | Temperature (K) | Method | Reference | Comment |
---|---|---|---|---|
5.81 | 236. | A | Stephenson and Malanowski, 1987 | Based on data from 184. to 251. K.; AC |
5.78 | 236. | N/A | Spence and Wild, 1935, 2 | Based on data from 173. to 251. K. See also Stephenson and Malanowski, 1987.; AC |
Antoine Equation Parameters
log10(P) = A − (B / (T + C))
P = vapor pressure (atm)
T = temperature (K)
View plot Requires a JavaScript / HTML 5 canvas capable browser.
Temperature (K) | A | B | C | Reference | Comment |
---|---|---|---|---|---|
163.76 to 250.86 | 4.27605 | 959.43 | -29.758 | Spence and Wild, 1935, 3 | Coefficents calculated by NIST from author's data. |
Enthalpy of fusion
ΔfusH (kcal/mol) | Temperature (K) | Reference | Comment |
---|---|---|---|
1.80 | 155. | Vasil'ev and Lebedev, 1998 | AC |
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
L - Sharon G. Lias
Data compiled as indicated in comments:
B - John E. Bartmess
MM - Michael M. Meot-Ner (Mautner)
LL - Sharon G. Lias and Joel F. Liebman
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
View reactions leading to CH2O+ (ion structure unspecified)
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
IE (evaluated) | 10.88 ± 0.01 | eV | N/A | N/A | L |
Quantity | Value | Units | Method | Reference | Comment |
Proton affinity (review) | 170.4 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
Gas basicity | 163.3 | kcal/mol | N/A | Hunter and Lias, 1998 | HL |
Quantity | Value | Units | Method | Reference | Comment |
ΔfH°(+) ion | 225.1 | kcal/mol | N/A | N/A | |
Quantity | Value | Units | Method | Reference | Comment |
ΔfH(+) ion,0K | 226.1 | kcal/mol | N/A | N/A |
Proton affinity at 298K
Proton affinity (kcal/mol) | Reference | Comment |
---|---|---|
170.1 ± 0.50 | Bouchoux and Leblanc, 2000 | T = 300K; MM |
Gas basicity at 298K
Gas basicity (review) (kcal/mol) | Reference | Comment |
---|---|---|
162.9 ± 0.2 | Bouchoux and Leblanc, 2000 | T = 300K; MM |
Ionization energy determinations
IE (eV) | Method | Reference | Comment |
---|---|---|---|
10.88 | CI | Ohno, Okamura, et al., 1995 | LL |
10.8887 ± 0.0030 | PE | Niu, Shirley, et al., 1993 | LL |
10.86 | PI | Traeger, 1985 | LBLHLM |
10.88 | PE | Kimura, Katsumata, et al., 1981 | LLK |
10.9 | PE | Von Niessen, Bieri, et al., 1980 | LLK |
10.885 ± 0.005 | PE | Hernandez, Masclet, et al., 1977 | LLK |
10.874 ± 0.002 | S | Drury-Lessard and Moule, 1977 | LLK |
10.868 ± 0.005 | PI | Guyon, Chupka, et al., 1976 | LLK |
10.88 ± 0.02 | PI | Warneck, 1971 | LLK |
10.87 ± 0.01 | PI | Mentall, Gentieu, et al., 1971 | LLK |
10.88 ± 0.02 | PI | Matthews and Warneck, 1969 | RDSH |
10.884 | PE | Baker, Baker, et al., 1968 | RDSH |
10.86 ± 0.02 | EI | Kanomata, 1961 | RDSH |
10.90 ± 0.03 | PI | Vilesov, 1960 | RDSH |
10.87 ± 0.01 | PI | Watanabe, 1957 | RDSH |
10.88 ± 0.01 | S | Price, 1935 | RDSH |
10.1 | PE | Rao, 1975 | Vertical value; LLK |
Appearance energy determinations
Ion | AE (eV) | Other Products | Method | Reference | Comment |
---|---|---|---|---|---|
CHO+ | 11.97 | H | PI | Traeger, 1985 | LBLHLM |
CHO+ | 13.94 ± 0.40 | H | EI | Wankenne, Caprace, et al., 1984 | LBLHLM |
CHO+ | 11.92 ± 0.01 | H | PI | Guyon, Chupka, et al., 1976 | LLK |
CHO+ | 11.89 ± 0.03 | H | PI | Warneck, 1971 | LLK |
CHO+ | 11.95 ± 0.06 | H | PI | Matthews and Warneck, 1969 | RDSH |
CO+ | 14.10 ± 0.08 | H2 | PI | Guyon, Chupka, et al., 1976 | LLK |
CO+ | 18.7 ± 0.2 | ? | EI | Brand and Reed, 1957 | RDSH |
H+ | 17.41 ± 0.07 | CHO | PI | Warneck, 1971 | LLK |
H2+ | 15.42 ± 0.06 | CO | PI | Warneck, 1971 | LLK |
De-protonation reactions
CHO- + =
Quantity | Value | Units | Method | Reference | Comment |
---|---|---|---|---|---|
ΔrH° | 394.52 ± 0.23 | kcal/mol | D-EA | Murray, Miller, et al., 1986 | gas phase; B |
Quantity | Value | Units | Method | Reference | Comment |
ΔrG° | 386.65 ± 0.40 | kcal/mol | H-TS | Murray, Miller, et al., 1986 | gas phase; B |
ΔrG° | 394.0 ± 4.5 | kcal/mol | IMRB | Karpas and Klein, 1975 | gas phase; 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.
Spence and Wild, 1935
Spence, R.; Wild, W.,
The Vapor Pressure Curve of Formaldehyde and Some Related Data,
J. Chem. Soc., 1935, 1935, 506-9. [all data]
Anonymous, 1958
Anonymous, R.,
, Am. Pet. Inst. Res. Proj. 45, Ohio State Univ., 1958. [all data]
Harries, 1901
Harries, C.D.,
Chem. Ber., 1901, 34, 635. [all data]
Stephenson and Malanowski, 1987
Stephenson, Richard M.; Malanowski, Stanislaw,
Handbook of the Thermodynamics of Organic Compounds, 1987, https://doi.org/10.1007/978-94-009-3173-2
. [all data]
Spence and Wild, 1935, 2
Spence, Robert; Wild, William,
114. The vapour-pressure curve of formaldehyde, and some related data,
J. Chem. Soc., 1935, 506, https://doi.org/10.1039/jr9350000506
. [all data]
Spence and Wild, 1935, 3
Spence, R.; Wild, W.,
The Vapour-Pressure Curve of Formaldehyde, and Some Related Data,
J. Chem. Soc., 1935, 138, 506-509, https://doi.org/10.1039/jr9350000506
. [all data]
Vasil'ev and Lebedev, 1998
Vasil'ev, V.G.; Lebedev, B.V.,
Thermodynamic Properties of Aliphatic Aldehydes and Polyaldehydes: Effect of Composition and Structure,
Polym. Sci., Ser. A, 1998, 40, 5, 464. [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]
Bouchoux and Leblanc, 2000
Bouchoux, G.; Leblanc, D.,
Gas-phase basicity of formaldehyde by the thermokinetic method,
European J. Mass Spectrom., 2000, 6, 443. [all data]
Ohno, Okamura, et al., 1995
Ohno, K.; Okamura, K.; Yamakado, H.; Hoshino, S.; Takami, T.; Yamauchi, M.,
Penning ionization of HCHO, CH2CH2, and CH2CHCHO by collision with He*(2 3S) metastable atoms,
J. Phys. Chem., 1995, 99, 14247. [all data]
Niu, Shirley, et al., 1993
Niu, B.; Shirley, D.A.; Bai, Y.,
High resolution photoelectron spectroscopy and femtosecond intramolecular dynamics of H2CO+ and D2CO+,
J. Chem. Phys., 1993, 98, 4377. [all data]
Traeger, 1985
Traeger, J.C.,
Heat of formation for the formyl cation by photoionization mass spectrometry,
Int. J. Mass Spectrom. Ion Processes, 1985, 66, 271. [all data]
Kimura, Katsumata, et al., 1981
Kimura, K.; Katsumata, S.; Achiba, Y.; Yamazaki, T.; Iwata, S.,
Ionization energies, Ab initio assignments, and valence electronic structure for 200 molecules
in Handbook of HeI Photoelectron Spectra of Fundamental Organic Compounds, Japan Scientific Soc. Press, Tokyo, 1981. [all data]
Von Niessen, Bieri, et al., 1980
Von Niessen, W.; Bieri, G.; Asbrink, L.,
30.4 nm He(II) photoelectron spectra of organic molecules. Part III. Oxo-compounds (C,H,O),
J. Electron Spectrosc. Relat. Phenom., 1980, 21, 175. [all data]
Hernandez, Masclet, et al., 1977
Hernandez, R.; Masclet, P.; Mouvier, G.,
Spectroscopie de photoelectrons d'aldehydes et de cetones aliphatiques,
J. Electron Spectrosc. Relat. Phenom., 1977, 10, 333. [all data]
Drury-Lessard and Moule, 1977
Drury-Lessard, C.R.; Moule, D.C.,
The higher Rydberg states of formaldehyde,
Chem. Phys. Lett., 1977, 47, 300. [all data]
Guyon, Chupka, et al., 1976
Guyon, P.M.; Chupka, W.A.; Berkowitz, J.,
Photoionization mass spectrometric study of formaldehyde H2CO, HDCO, and D2CO,
J. Chem. Phys., 1976, 65, 1419. [all data]
Warneck, 1971
Warneck, P.,
Photoionisation von methanol und formaldehyd,
Z. Naturforsch. A:, 1971, 26, 2047. [all data]
Mentall, Gentieu, et al., 1971
Mentall, J.E.; Gentieu, E.P.; Krauss, M.; Neumann, D.,
Photoionization and absorption spectrum of formaldehyde in the vacuum ultraviolet,
J. Chem. Phys., 1971, 55, 5471. [all data]
Matthews and Warneck, 1969
Matthews, C.S.; Warneck, P.,
Heats of formation of CHO+ and C3H3+ by photoionization,
J. Chem. Phys. 5, 1969, 1, 854. [all data]
Baker, Baker, et al., 1968
Baker, A.D.; Baker, C.; Brundle, C.R.; Turner, D.W.,
The electronic structures of methane, ethane, ethylene and formaldehyde studied by high-resolution molecular photoelectron spectroscopy,
Intern. J. Mass Spectrom. Ion Phys., 1968, 1, 285. [all data]
Kanomata, 1961
Kanomata, I.,
Mass-spectrometric study on ionization and dissociation of formaldehyde, acetaldehyde, acetone and ethyl methyl ketone by electron impact,
Bull. Chem. Soc. Japan, 1961, 34, 1864. [all data]
Vilesov, 1960
Vilesov, F.I.,
The photoionization of vapors of compounds whose molecules contain carbonyl groups,
Dokl. Phys. Chem., 1960, 132, 521, In original 1332. [all data]
Watanabe, 1957
Watanabe, K.,
Ionization potentials of some molecules,
J. Chem. Phys., 1957, 26, 542. [all data]
Price, 1935
Price, W.C.,
The far ultraviolet absorption spectra of formaldehyde and the alkyl derivatives of H, O and H2S,
J. Chem. Phys., 1935, 3, 256. [all data]
Rao, 1975
Rao, C.N.R.,
Lone-pair ionization bands of chromophores in the photoelectron spectra of organic molecules,
Indian J. Chem., 1975, 13, 950. [all data]
Wankenne, Caprace, et al., 1984
Wankenne, H.; Caprace, G.; Momigny, J.,
Unimolecular decay of metastable ions in formaldehyde,
Int. J. Mass Spectrom. Ion Processes, 1984, 57, 149. [all data]
Brand and Reed, 1957
Brand, J.C.D.; Reed, R.I.,
The electronic spectrum of formaldehyde. Part II. Mechanisms of dissociation of formaldehyde and the formaldehyde molecular ion,
J. Chem. Soc., 1957, 2386. [all data]
Murray, Miller, et al., 1986
Murray, K.K.; Miller, T.M.; Leopold, D.G.; Lineberger, W.C.,
Laser photoelectron spectroscopy of the Formylf anion,
J. Chem. Phys., 1986, 84, 2520. [all data]
Karpas and Klein, 1975
Karpas, Z.; Klein, F.S.,
Negative ion-molecule reactions in a mixture of ammonia-formaldehyde - an ICR mass spectrometry study,
Int. J. Mass Spectrom. Ion Phys., 1975, 18, 65. [all data]
Notes
Go To: Top, Phase change data, Gas phase ion energetics data, References
- Symbols used in this document:
AE Appearance energy IE (evaluated) Recommended ionization energy Tboil Boiling point Tfus Fusion (melting) point Ttriple Triple point temperature ΔfH(+) ion,0K Enthalpy of formation of positive ion at 0K ΔfusH Enthalpy of fusion 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
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