Urea
- Formula: CH4N2O
- Molecular weight: 60.0553
- IUPAC Standard InChI: InChI=1S/CH4N2O/c2-1(3)4/h(H4,2,3,4)
- IUPAC Standard InChIKey: XSQUKJJJFZCRTK-UHFFFAOYSA-N
- 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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Gas phase thermochemistry data
Go To: Top, Condensed phase thermochemistry data, Reaction thermochemistry 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: Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°gas | -235.5 ± 1.2 | kJ/mol | Ccb | Kabo, Miroshnichenko, et al., 1990 | see Simirsky, Kabo, et al., 1987 |
Condensed phase thermochemistry data
Go To: Top, Gas phase thermochemistry data, Reaction thermochemistry 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:
ALS - Hussein Y. Afeefy, Joel F. Liebman, and Stephen E. Stein
DH - Eugene S. Domalski and Elizabeth D. Hearing
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔfH°solid | -333.11 ± 0.69 | kJ/mol | Ccb | Kabo, Miroshnichenko, et al., 1990 | see Simirsky, Kabo, et al., 1987; ALS |
| ΔfH°solid | -320.2 ± 2.0 | kJ/mol | Ccb | Contineanu, Wagner, et al., 1982 | ALS |
| ΔfH°solid | -333.39 ± 0.17 | kJ/mol | Ccb | Johnson, 1975 | ALS |
| ΔfH°solid | -333.3 ± 0.2 | kJ/mol | Ccb | Huffman, 1940 | ALS |
| ΔfH°solid | -323.6 | kJ/mol | Ccb | Schmidt and Becker, 1933 | ALS |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔcH°solid | -635. ± 8. | kJ/mol | AVG | N/A | Average of 8 values; Individual data points |
| Quantity | Value | Units | Method | Reference | Comment |
| S°solid,1 bar | 104.26 | J/mol*K | N/A | Andersson, Matsuo, et al., 1993 | DH |
| S°solid,1 bar | 104.93 | J/mol*K | N/A | Kozyro, Dalidovich, et al., 1986 | DH |
| S°solid,1 bar | 105.4 | J/mol*K | N/A | Parks, Huffman, et al., 1933 | Extrapolation below 90 K, 33.18 J/mol*K.; DH |
| S°solid,1 bar | 172. | J/mol*K | N/A | Gibson, Latimer, et al., 1920 | Extrapolation below 86 K, no details.; DH |
Constant pressure heat capacity of solid
| Cp,solid (J/mol*K) | Temperature (K) | Reference | Comment |
|---|---|---|---|
| 92.79 | 298.15 | Andersson, Matsuo, et al., 1993 | T = 15 to 310 K.; DH |
| 94.0 | 304.7 | Gambino and Bros, 1988 | T = 303 to 413 K.; DH |
| 93.08 | 298.15 | Kozyro, Dalidovich, et al., 1986 | T = 5 to 400 K. Cp = 38.43 + 4.98x10-2T + 7.05x10-4T2 - 8.61x10-7T3 (240 to 400 K).; DH |
| 90.0 | 298.15 | Sasaki and Yokotake, 1966 | T = 90 to 298 K.; DH |
| 93.14 | 298.15 | Ruehrwein and Huffman, 1946 | T = 19 to 318 K.; DH |
| 68.6 | 293. | Campbell and Campbell, 1940 | DH |
| 93.64 | 298.0 | Parks, Huffman, et al., 1933 | T = 93 to 298 K. Value is unsmoothed experimental datum.; DH |
| 115.5 | 298.0 | Gibson, Latimer, et al., 1920 | T = 86 to 300 K. Value is unsmoothed experimental datum.; DH |
Reaction thermochemistry data
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry 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
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
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 1514. ± 12. | kJ/mol | CIDC | Ma, Wang, et al., 1998 | gas phase; H and S (20.5±1.8 eu) directly from kinetic method; B |
| ΔrH° | 1517. ± 11. | kJ/mol | G+TS | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
| ΔrH° | 1495. ± 8.8 | kJ/mol | EIAE | Muftakhov, Vasil'ev, et al., 1999 | gas phase; B |
| Quantity | Value | Units | Method | Reference | Comment |
| ΔrG° | 1488. ± 13. | kJ/mol | H-TS | Ma, Wang, et al., 1998 | gas phase; H and S (20.5±1.8 eu) directly from kinetic method; B |
| ΔrG° | 1487. ± 10. | kJ/mol | IMRE | Taft, 1987 | gas phase; value altered from reference due to change in acidity scale; B |
+
=
By formula: CH4N2O + C4H4O2 = N-(aminocarbonyl)-3-oxobutyramide
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | -106.4 | kJ/mol | Kin | Lopatin, Popov, et al., 1992 | liquid phase; solvent: Solution; ALS |
6 =
+ 3
+ 6
By formula: 6CH4N2O = C3H6N6 + 3CO2 + 6H3N
| Quantity | Value | Units | Method | Reference | Comment |
|---|---|---|---|---|---|
| ΔrH° | 469.4 | kJ/mol | Eqk | Rukevich and Zagranichnyi, 1971 | liquid phase; ALS |
References
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, 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]
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]
Notes
Go To: Top, Gas phase thermochemistry data, Condensed phase thermochemistry data, Reaction thermochemistry data, 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) 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 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
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