Urea

• Formula: CH₄N₂O
• Molecular weight: 60.0553
• IUPAC Standard InChI: InChI=1S/CH4N2O/c2-1(3)4/h(H4,2,3,4) Copy

  
• IUPAC Standard InChIKey: XSQUKJJJFZCRTK-UHFFFAOYSA-N Copy
• CAS Registry Number: 57-13-6
• 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: Carbamide; Carbamimidic acid; Carbonyldiamide; Isourea; Pseudourea; Urea-13C; Ureaphil; Ureophil; Urevert; UR; (NH2)2CO; Carbonyl Diamine; Alphadrate; Aquacare; Aquadrate; B-I-K; Calmurid; Carbaderm; Keratinamin; NCI-C02119; Pastaron; Prespersion, 75 urea; Ultra Mide; Urepearl; Mocovina; Supercel 3000; Varioform II; Benural 70; Harnstoff; Basodexan; Bubber shet; Elaqua xx; Hyanit; Nutraplus; Onychomal; NSC 34375; Uroderm; Panafil (Salt/Mix); Cerovel (Salt/Mix); component of Artra Ashy Skin Cream (Salt/Mix)
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• Information on this page:
  • Gas phase thermochemistry data
  • Condensed phase thermochemistry data
  • Phase change data
  • Reaction thermochemistry data
  • IR Spectrum
  • Mass spectrum (electron ionization)
  • UV/Visible spectrum
  • References
  • Notes
• Other data available:
  • Gas phase ion energetics data
• Data at other public NIST sites:
  • X-ray Photoelectron Spectroscopy Database, version 5.0
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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.

Data compiled by: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

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.

Data compiled as indicated in comments:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Constant pressure heat capacity of solid

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.

Data compiled as indicated in comments:
TRC - Thermodynamics Research Center, NIST Boulder Laboratories, Chris Muzny director
AC - William E. Acree, Jr., James S. Chickos
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing

Enthalpy of sublimation

Enthalpy of fusion

Entropy of fusion

Reaction 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.

Data compiled as indicated in comments:
B - John E. Bartmess
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein

Note: Please consider using the reaction search for this species. This page allows searching of all reactions involving this species. A general reaction search form is also available. Future versions of this site may rely on reaction search pages in place of the enumerated reaction displays seen below.

Individual Reactions

CH₃N₂O^- +  =

By formula: CH₃N₂O^- + H⁺ = CH₄N₂O

 +  =

By formula: CH₄N₂O + C₄H₄O₂ = N-(aminocarbonyl)-3-oxobutyramide

6 =  + 3 + 6

By formula: 6CH₄N₂O = C₃H₆N₆ + 3CO₂ + 6H₃N

IR Spectrum

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Data compiled by: Coblentz Society, Inc.

• SOLID (SPLIT MULL, FLUOROLUBE FOR 3800-1333 AND NUJOL FOR 1333-450 CM ^-1); DOW KBr FOREPRISM-GRATING; DIGITIZED BY NIST FROM HARD COPY (FROM TWO SEGMENTS); 4 cm^-1 resolution

Data compiled by: Timothy J. Johnson, Tanya L. Myers, Yin-Fong Su, Russell G. Tonkyn, Molly Rose K. Kelly-Gorham, and Tyler O. Danby

• solid; Bruker Tensor 37 FTIR; 0.96450084 cm^-1 resolution

Mass spectrum (electron ionization)

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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 by: NIST Mass Spectrometry Data Center, William E. Wallace, director

Spectrum

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Additional Data

UV/Visible spectrum

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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 by: Victor Talrose, Alexander N. Yermakov, Alexy A. Usov, Antonina A. Goncharova, Axlexander N. Leskin, Natalia A. Messineva, Natalia V. Trusova, Margarita V. Efimkina

Spectrum

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Additional Data

References

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, Notes

Data compilation copyright by the U.S. Secretary of Commerce on behalf of the U.S.A. All rights reserved.

Kabo, Miroshnichenko, et al., 1990
Kabo, G.Ya.; Miroshnichenko, E.A.; Frenkel, M.L.; Kozyro, A.A.; Simirskii, V.V.; Krasulin, A.P.; Vorob'eva, V.P.; Lebedev, Yu.A., Thermochemistry of urea alkyl derivatives, Bull. Acad. Sci. USSR, Div. Chem. Sci., 1990, 662-667. [all data]

Simirsky, Kabo, et al., 1987
Simirsky, V.V.; Kabo, G.J.; Frenkel, M.L., Additivity of the enthalpies of formation of urea derivatives in the crystalline state, J. Chem. Thermodyn., 1987, 19, 1121-1127. [all data]

Contineanu, Wagner, et al., 1982
Contineanu, I.; Wagner, L.; Stanescu, L.; Marchidan, D.I., Combustion and formation enthalpies of o-phenylenediamine, urea and 2-benzimidazolone, Rev. Roum. Chim., 1982, 27, 205-209. [all data]

Johnson, 1975
Johnson, W.H., The enthalpies of combustion and formation of acetanilide and urea, J. Res. NBS, 1975, 79, 487-491. [all data]

Huffman, 1940
Huffman, H.M., Thermal Data. XII. The heats of combustion of urea and guanidine carbonate and their standard free energies of formation, J. Am. Chem. Soc., 1940, 62, 1009-1011. [all data]

Schmidt and Becker, 1933
Schmidt, V.A.; Becker, F., Die Bildungswarme von Nitrocellulofen, Nitroglycerin und anderen widuigen Beltandteilen von Treibmitteln, Z. Gesamte Schiess Sprengstoffwes., 1933, 33, 280-282. [all data]

Andersson, Matsuo, et al., 1993
Andersson, O.; Matsuo, T.; Suga, H.; Ferloni, P., Low-temperature heat capacity of urea, Int. J. Thermophys., 1993, 14(1), 149-158. [all data]

Kozyro, Dalidovich, et al., 1986
Kozyro, A.A.; Dalidovich, S.V.; Krasulin, A.P., Heat capacity, enthalpy of fusion, and thermodynamic properties of urea, Zhur. Prikl. Khim. (Leningrad), 1986, 59, 1456-1459. [all data]

Parks, Huffman, et al., 1933
Parks, G.S.; Huffman, H.M.; Barmore, M., Thermal data on organic compounds. XI. The heat capacities, entropies and free energies of ten compounds containing oxygen or nitrogen. J. Am. Chem. Soc., 1933, 55, 2733-2740. [all data]

Gibson, Latimer, et al., 1920
Gibson, G.E.; Latimer, W.M.; Parks, G.S., Entropy changes at low temperatures. I. Formic acid and urea. A test of the third law of thermodynamics, J. Am. Chem. Soc., 1920, 42, 1533-1542. [all data]

Gambino and Bros, 1988
Gambino, M.; Bros, J.P., Capacite calorifique de l'uree et de quelques melanges eutectiques a base d'uree entre 30 et 140°C, Thermochim. Acta, 1988, 127, 223-236. [all data]

Sasaki and Yokotake, 1966
Sasaki, K.; Yokotake, T., Thermodynamic properties of the products in SO₃-NH₃ reaction. II. Specific heats of sulfamide and ammonium sulfamate, Tokyo Kogyo Shikenshi Hokohu, 1966, 61, 309-314. [all data]

Ruehrwein and Huffman, 1946
Ruehrwein, R.A.; Huffman, H.M., Thermal data. XIX. The heat capacity, entropy and free energy of urea, J. Am. Chem. Soc., 1946, 68, 1759-1761. [all data]

Campbell and Campbell, 1940
Campbell, A.N.; Campbell, A.J.R., The heats of solution, heats of formation, specific heats and equilibrium diagrams of certain molecular compounds. J. Am. Chem. Soc., 1940, 62, 291-297. [all data]

Ferloni and DellaGatta, 1995
Ferloni, P.; DellaGatta, G., Heat capacities of urea, N-methylurea, N-ethylurea, N-(n)propylurea, and N- (n)butylurea in the range 200 to 360 K, Thermochim. Acta, 1995, 266, 203-12. [all data]

Kabo, Miroshnichenko, et al., 1990, 2
Kabo, G.Ya.; Miroshnichenko, E.A.; Frenkel, M.L.; Kozyro, A.A.; Simirsky, V.V.; Krasulin, A.P.; Vorob'eva, V.P.; Lebedev, Yu.A., Thermochemistry of Alkyl Derivatives of Urea, Izv. Akad. Nauk SSSR, Ser. Khim., 1990, No. 4, 750-5. [all data]

Kozyro, Dalidovich, et al., 1986, 2
Kozyro, A.A.; Dalidovich, S.V.; Krausulin, A.P., Zh. Prikl. Khim. (S.-Peterburg), 1986, 59, 1456. [all data]

Vogel and Schuberth, 1980
Vogel, L.; Schuberth, H., Some physicochemical data of urea near the melting point<, Chem. Tech. (Leipzig), 1980, 32, 143. [all data]

Emel'yanenko, Kabo, et al., 2006
Emel'yanenko, Vladimir N.; Kabo, Gennady J.; Verevkin, Sergey P., Measurement and Prediction of Thermochemical Properties: Improved Increments for the Estimation of Enthalpies of Sublimation and Standard Enthalpies of Formation of Alkyl Derivatives of Urea, J. Chem. Eng. Data, 2006, 51, 1, 79-87, https://doi.org/10.1021/je050230z . [all data]

De Wit, Van Miltenburg, et al., 1983
De Wit, H.G.M.; Van Miltenburg, J.C.; De Kruif, C.G., Thermodynamic properties of molecular organic crystals containing nitrogen, oxygen, and sulphur 1. Vapour pressures and enthalpies of sublimation, The Journal of Chemical Thermodynamics, 1983, 15, 7, 651-663, https://doi.org/10.1016/0021-9614(83)90079-4 . [all data]

Suzuki, Onishi, et al., 1956
Suzuki, K.; Onishi, S.; Koide, T.; Seki, S., Vapor pressures of molecular crystals. XI. Vapor pressures of crystalline urea and diformylhydrazine. Energies of hydrogen bonds in these crystals, Bull. Chem. Soc. Jpn., 1956, 29, 127. [all data]

Zaitsau, Kabo, et al., 2003
Zaitsau, Dz; Kabo, G.J.; Kozyro, A.A.; Sevruk, V.M., The effect of the failure of isotropy of a gas in an effusion cell on the vapor pressure and enthalpy of sublimation for alkyl derivatives of carbamide, Thermochimica Acta, 2003, 406, 1-2, 17-28, https://doi.org/10.1016/S0040-6031(03)00231-4 . [all data]

Ferro, Barone, et al., 1987
Ferro, D.; Barone, G.; Della Gatta, G.; Piacente, V., Vapour pressures and sublimation enthalpies of urea and some of its derivatives, The Journal of Chemical Thermodynamics, 1987, 19, 9, 915-923, https://doi.org/10.1016/0021-9614(87)90038-3 . [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]

Trimble and Voorhoeve, 1978
Trimble, L.E.; Voorhoeve, R.J.H., Continuous colorimetric monitoring of vapour-phase urea and cyanates, Analyst, 1978, 103, 1228, 759, https://doi.org/10.1039/an9780300759 . [all data]

Suzuki, Onishi, et al., 1956, 2
Suzuki, Keisuke; Onishi, Shun-ichi; Koide, Tsutomu; Seki, Syuzo, Vapor Pressures of Molecular Crystals. XI. Vapor Pressures of Crystalline Urea and Diformylhydrazine. Energies of Hydrogen Bonds in these Crystals, Bull. Chem. Soc. Jpn., 1956, 29, 1, 127-131, https://doi.org/10.1246/bcsj.29.127 . [all data]

Jones, 1960
Jones, A.H., Sublimation Pressure Data for Organic Compounds., J. Chem. Eng. Data, 1960, 5, 2, 196-200, https://doi.org/10.1021/je60006a019 . [all data]

Cox and Pilcher, 1970
Cox, J.D.; Pilcher, G., Thermochemistry of Organic and Organometallic Compounds, Academic Press Inc., London, 1970, 643. [all data]

Bradley and Cleasby, 1953
Bradley, R.S.; Cleasby, T.G., 346. The vapour pressure and lattice energy of hydrogen-bonded crystals. Part I. Oxamide, oxamic acid, and rubeanic acid, J. Chem. Soc., 1953, 1681, https://doi.org/10.1039/jr9530001681 . [all data]

Della Gatta and Ferro, 1987
Della Gatta, G.; Ferro, D., Enthalpies of fusion and solid-to-solid transition, entropies of fusion for urea and twelve alkylureas, Thermochim. Acta, 1987, 122, 143-152. [all data]

Vogel and Schuberth, 1980, 2
Vogel, L.; Schuberth, H., Some physicochemical data of urea near the melting point, Chem. Tech. (Leipzig), 1980, 32, 143-144. [all data]

Rai and Rai, 1999
Rai, U.S.; Rai, R.N., Some Physicochemical Studies on Organic Eutectics and Molecular Complex: Urea -- p-nitrophenol System, J. Mater. Res., 1999, 14, 04, 1299-1305, https://doi.org/10.1557/JMR.1999.0177 . [all data]

Jamróz, Palczewska-Tulinska, et al., 1998
Jamróz, Malgorzata E.; Palczewska-Tulinska, Marcela; Wyrzykowska-Stankiewicz, Danuta; Szafranski, Andrzej M.; Polaczek, Jerzy; Dobrowolski, Jan Cz.; Jamróz, Michal H.; Mazurek, Aleksander P., The urea--phenol(s) systems, Fluid Phase Equilibria, 1998, 152, 2, 307-326, https://doi.org/10.1016/S0378-3812(98)90206-0 . [all data]

Rai and Rai, 1998
Rai, U.S.; Rai, R.N., Journal of Thermal Analysis and Calorimetry, 1998, 53, 3, 883-893, https://doi.org/10.1023/A:1010190402954 . [all data]

Ferloni and Gatta, 1995
Ferloni, Paolo; Gatta, Giuseppe Della, Heat capacities of urea, N-methylurea, N-ethylurea, N-(n)propylurea, and N-(n)butylurea in the range 200 to 360 K, Thermochimica Acta, 1995, 266, 203-212, https://doi.org/10.1016/0040-6031(95)02453-0 . [all data]

Ma, Wang, et al., 1998
Ma, S.G.; Wang, F.; Cooks, R.G., Gas-phase acidity of urea, J. Mass Spectrom., 1998, 33, 10, 943-949, https://doi.org/10.1002/(SICI)1096-9888(1998100)33:10<943::AID-JMS703>3.0.CO;2-B . [all data]

Taft, 1987
Taft, R.W., The Nature and Analysis of Substitutent Electronic Effects, Personal communication. See also Prog. Phys. Org. Chem., 1987, 16, 1. [all data]

Muftakhov, Vasil'ev, et al., 1999
Muftakhov, M.V.; Vasil'ev, Y.V.; Mazunov, V.A., Determination of electron affinity of carbonyl radicals by means of negative ion mass spectrometry, Rapid Commun. Mass Spectrom., 1999, 13, 12, 1104-1108, https://doi.org/10.1002/(SICI)1097-0231(19990630)13:12<1104::AID-RCM619>3.0.CO;2-C . [all data]

Lopatin, Popov, et al., 1992
Lopatin, E.B.; Popov, V.V.; Epshtein, N.A.; Mikhaleva, L.M.; Makarov, Yu.N., Kinetic and thermochemical characteristics of diketene-based reactions, Khim.-Farm. Zh., 1992, 26, 76-78. [all data]

Rukevich and Zagranichnyi, 1971
Rukevich, O.S.; Zagranichnyi, V.I., Equilibrium in the reaction of melamine formation from urea, J. Anal. Chem. USSR, 1971, 44, 1616-1620. [all data]

Klotz and Askounts, 1947
Klotz, I.M.; Askounts, T., J. Am. Chem. Soc., 1947, 69, 801. [all data]

Notes

Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Phase change data, Reaction thermochemistry data, IR Spectrum, Mass spectrum (electron ionization), UV/Visible spectrum, References

• Symbols used in this document:
  

  Cp,solid	Constant pressure heat capacity of solid
  S°solid,1 bar	Entropy of solid at standard conditions (1 bar)
  Tfus	Fusion (melting) point
  Ttriple	Triple point temperature
  ΔcH°solid	Enthalpy of combustion of solid at standard conditions
  ΔfH°gas	Enthalpy of formation of gas at standard conditions
  ΔfH°solid	Enthalpy of formation of solid at standard conditions
  ΔfusH	Enthalpy of fusion
  ΔfusS	Entropy of fusion
  ΔrG°	Free energy of reaction at standard conditions
  ΔrH°	Enthalpy of reaction at standard conditions
  ΔsubH	Enthalpy of sublimation
  ΔsubH°	Enthalpy of sublimation at standard conditions

• Data from NIST Standard Reference Database 69: NIST Chemistry WebBook
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