Urea
General
Systematic name	Diaminomethanal
Other names	?
Molecular formula	(NH2)2CO
SMILES	NC(=O)N
Molar mass	60.07 g/mol
Appearance	white odourless solid
CAS number	[57-13-6]
Properties
Density and phase	750 kg/m3
Solubility in water	108 g/100 ml (20 °C) 167 g/100 ml (40 °C) 251 g/100 ml (60 °C) 400 g/100 ml (80 °C) 733 g/100 ml (100 °C)
Melting point	132.7 °C (406 K) decomposes
Boiling point	n.a.
Acidity (pKa)	0.18
Basicity (pKb)	13.82
Chiral rotation [α]D	Not chiral
Viscosity	? cP at ? °C
Critical relative humidity	81% (20°C) 73% (30°C)
Heat of solution in water	-57,8 cal/g (endothermic)
Nitrogen content	46,6 %N
Structure
Molecular shape	?
Coordination geometry	trigonal planar
Crystal structure	?
Dipole moment	? D
Hazards
MSDS	J.T. Baker
Main hazards	?
Flash point	? °C
R/S statement	R: ? S: ?
RTECS number	?
NFPA 704	estimated
Supplementary data page
Structure & properties	n, εr, etc.
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Other anions	?
Other cations	?
Related ?	biuret triuret thiourea
Related compounds	?
Except where noted otherwise, data are given for materials in their standard state (at 26°C, 100 kPa) Infobox disclaimer and references

Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON₂H₄ or (NH₂)₂CO. Structure of Urea, created with ChemSketch. ... Image File history File links Download high-resolution version (1100x1069, 220 KB) File links The following pages on the English Wikipedia link to this file (pages on other projects are not listed): Urea ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... Density (symbol: ρ - Greek: rho) is a measure of mass per volume. ... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... This article describes water from a scientific and technical perspective. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... In chemistry and biochemistry, the acid dissociation constant, the acidity constant, or the acid-ionization constant (Ka) is a specific type of equilibrium constant that indicates the extent of dissociation of hydrogen ions from an acid. ... In chemistry and biochemistry, the acid dissociation constant, the acidity constant, or the acid-ionization constant (Ka) is a specific type of equilibrium constant that indicates the extent of dissociation of hydrogen ions from an acid. ... The specific rotation of a chemical compound [α]D is defined as the observed angle of optical rotation α when light of 589 nanometer wavelength (the sodium D line) is passed through a sample with a path length of 0. ... The pitch drop experiment at the University of Queensland. ... The poise (P) is the cgs unit of viscosity, 1 P = 1 g·cm-1·s-1 The SI analog is 1 pascal second (Pa·s) = 1 kg·m-1·s-1 = 10 P. It is named after Jean Louis Marie Poiseuille. ... The critical relative humidity (CRH) of a salt is defined as the relative humidity of the surrounding atmosphere (at a certain temperature) at which the material begins to absorb moisture from the atmosphere and below which it will not absorb atmospheric moisture. ... four sp³ orbitals three sp² orbitals In chemistry, hybridisation or hybridization (see also spelling differences) is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for the qualitative description of atomic bonding properties. ... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... // The Earths magnetic field, which is approximately a dipole. ... The debye (symbol: D) is a non-SI and non-CGS unit of electrical dipole moment. ... A material safety data sheet or MSDS is a form containing data regarding the properties of a particular substance. ... The examples and perspective in this article or section may not represent a worldwide view. ... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... Risk and Safety Statements, also known as R/S statements, R/S numbers, R/S phrases, and R/S sentences, is a system of hazard codes and phrases for labeling dangerous chemicals and compounds. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... NFPA 704 is a standard maintained by the U.S. National Fire Protection Association. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Image File history File links File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... The refractive index (or index of refraction) of a material is the factor by which the phase velocity of electromagnetic radiation is slowed in that material, relative to its velocity in a vacuum. ... The dielectric constant εr (represented as or K in some cases) is defined as the ratio: where εs is the static permittivity of the material in question, and ε0 is the vacuum permittivity. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... IR spectrum of a thin film of liquid ethanol. ... Nuclear Magnetic Resonance Spectroscopy most commonly known as NMR Spectroscopy is the name given to the technique which exploits the magnetic properties of nuclei. ... Basic schematic of a mass spectrometer Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or in common speech mass-spec) is an analytical technique used to measure the mass-to-charge ratio of ions. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss or addition of one or more electrons. ... An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss or addition of one or more electrons. ... A question mark is a punctuation mark. ... Biuret is a chemical compound with the chemical formula C2O2N3H5. ... Thiourea is related to urea, where an oxygen atom is replaced by a sulfur atom. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... Benzene An organic compound is any member of a large class of chemical compounds whose molecules contain carbon, with the exception of carbides, carbonates, carbon oxides and elementary carbon. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... A chemical formula (also called molecular formula) is a concise way of expressing information about the atoms that constitute a particular chemical compound. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Atomic mass 12. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Atomic mass 15. ...

Urea is also known as carbamide, especially in the recommended International Non-proprietary Names (rINN) in use in Europe. For example, the medicinal compound hydroxyurea (old British Approved Name) is now hydroxycarbamide. Other names include carbamide resin, isourea, carbonyl diamide, and carbonyldiamine. Hydroxyurea or hydroxycarbamide (brand names include Hydrea®) is an antineoplastic drug used in hematological malignancies. ...

Discovery

Urea was discovered by Hilaire Rouelle in 1773. It was the first organic compound to be artificially synthesized from inorganic starting materials, in 1828 by Friedrich Woehler, who prepared it by the reaction of potassium cyanate with ammonium sulfate. Although Woehler was attempting to prepare ammonium cyanate, by forming urea, he inadvertently disproved vitalism, the theory that the chemicals of living organisms are fundamentally different from inanimate matter, thus starting the discipline of organic chemistry. Hilaire Marin Rouelle (1718 - 1779) was a French chemist. ... 1773 was a common year starting on Friday (see link for calendar). ... 1828 was a leap year starting on Tuesday (see link for calendar). ... Friedrich Wöhler Friedrich Wöhler (July 31, 1800 - September 23, 1882) was a German chemist, best-known for his synthesis of urea, but also the first to isolate several of the elements. ... Potassium cyanate or potassium isocyanate is an inorganic compound and the potassium salt of cyanic acid with the chemical formula of KOCN (also: KCNO). ... Ammonium sulfate, (NH4)2SO4, sometimes known as Mohrs Salt, is a chemical compound commonly used as a fertilizer. ... Vitalism is the doctrine that vital forces are active in living organisms, so that life cannot be explained solely by mechanism. ... Organic chemistry is a specific discipline within the subject of chemistry. ...

Physiology

The individual atoms that make up a urea molecule come from carbon dioxide, water, aspartate and ammonia in a metabolic pathway known as the urea cycle, an anabolic process. This expenditure of energy is necessary because ammonia, a common metabolic waste product, is toxic and must be neutralized. Urea production occurs in the liver and is under the regulatory control of N-acetylglutamate. Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... Aspartic acid, also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ... Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell, catalyzed by enzymes, resulting in either the formation of a metabolic product to be used or stored by the cell, or the initiation of another metabolic pathway (then called a flux generating step). ... The Urea Cycle is a cycle of biochemical reactions occurring in many animal organisms that produces urea from ammonia. ... Anabolism is the metabolic process that builds larger molecules from smaller ones. ... It has been suggested that this article or section be merged with cell metabolism and carbohydrates. ... The liver is an organ in living beings, including humans. ...

Most organisms have to deal with the excretion of nitrogen waste originating from protein and amino acid catabolism. In aquatic organisms the most common form of nitrogen waste is ammonia, while land-dwelling organisms developed ways to convert the toxic ammonia to either urea or uric acid. Generally, birds and saurian reptiles excrete uric acid, while the remaining species, including mammals, excrete urea. Remarkably, tadpoles excrete ammonia, and shift to urea production during metamorphosis. In veterinary medicine, Dalmation breeds of dogs are different in that they excrete urea in the form of uric acid in the urine rather than in the urea form. This is due to a defect in one of the genes controlling expression of the conversion enzymes in the Urea cycle. A crab is an example of an organism. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... The general structure of an α-amino acid molecule, with the amine group on the left and the carboxyl group on the right. ... Anabolism is the aspect of metabolism that contributes to growth. ... Marine life can be very abundant. ... This article or section is in need of attention from an expert on the subject. ... The sarrukh are a fictitious race of reptilian humanoids in the Forgotten Realms setting of Dungeons & Dragons. ... Orders Procolophonia (extinct) Testudines Araeoscelidia (extinct) Avicephala (extinct) Younginiformes (extinct) Sauropterygia Ichthyosauria (extinct) Placodontia (extinct) Nothosauria (extinct) Plesiosauria (extinct) Sphenodontia Squamata Prolacertiformes (extinct) Archosauria Crurotarsi Order Aetosauria (extinct) Order Phytosauria(extinct) Order Rauisuchia (extinct) Order Crocodilia Ornithodira Pterosauria (extinct) Marasuchus (extinct) Dinosauria Order Saurischia Order Ornithischia(extinct) Reptiles are tetrapods... Orders Multituberculata (extinct) Palaeoryctoides (extinct) Triconodonta (extinct) Subclass Australosphenida Ausktribosphenida Monotremata Subclass Eutheria (excludes extinct ancestors) Afrosoricida Anagaloidea (extinct) Arctostylopida (extinct) Artiodactyla Carnivora Cetacea Chiroptera Cimolesta (extinct) Cingulata Creodonta (extinct) Condylarthra (extinct) Dermoptera Desmostylia (extinct) Dinocerata (extinct) Embrithopoda (extinct) Hyracoidea Insectivora Lagomorpha Leptictida (extinct) Litopterna (extinct) Macroscelidea Mesonychia (extinct) Notoungulata... Tadpole of Littlejohns Tree Frog (Litoria littlejohni) A tadpole (also known as a pollywog or polliwog) is a larval amphibian, the juvenile form of a frog, toad, newt, salamander, or caecilian. ... A Pieris rapae larva An older Pieris rapae larva A Pieris rapae pupa A Pieris rapae adult Metamorphosis is a process in biology by which an individual physically develops after birth or hatching, and involves significant change in form as well as growth and differentiation. ...

The urea is formed in the livers of mammals in a cyclic pathway, from the break down of ammonia, (a metabolic waste), which was initially named the Krebs-Henseleit cycle after its discoverers, and later became known simply as the urea cycle. This cycle was partially deduced by Krebs & Henseleit in 1932 and was clarified in the 1940s as the roles of citrulline and argininosuccinate as intermediates were understood. Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... Synonyms: Urea cycle A sequence of chemical reactions that was partially deduced by Kurt Henseleit and Sir Hans Adolf Krebs, occurring primarily in the liver, by which ammonia is converted to urea in mammalian tissue. ... The Urea Cycle is a cycle of biochemical reactions occurring in many animal organisms that produces urea from ammonia. ... Krebs may refer to: Brian Krebs, Washington Post technology reporter Ed Krebs, photographer Edwin G. Krebs Ernst T. Krebs chemist Hans Krebs (general) Hans Adolf Krebs, doctor for whom the Krebs cycle is named Hans Krebs (National Socialist) Johann Ludwig Krebs Johann Tobias Krebs John Krebs, scientist and first chairman... The chemical compound citrulline is an α-amino acid (AA). ... Arginosuccinic acid is a chemical compound that belongs to the class of the amino acids. ...

In this cycle, amino groups donated by ammonia and L-aspartate are converted to urea, while L-ornithine, citrulline, L-arginino-succinate, and L-arginine act as intermediates. In chemistry, especially in organic chemistry and biochemistry, an amino group is an ammonia-like functional group. ... Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... Aspartic acid, also known as aspartate, the name of its anion, is one of the 20 natural proteinogenic amino acids which are the building blocks of proteins. ... Ornithine is an amino acid, whose structure is: NH2-CH2-CH2-CH2-CHNH2-COOH Ornithine is one of the products of the action of the enzyme arginase on L-arginine, creating urea. ... Arginine (symbol Arg or R) is an α-amino acid. ...

Despite the generalization above, the pathway has been documented not only in mammals and amphibians, but in many other organisms as well, including birds, invertebrates, insects, plants, yeast, fungi, and even microorganisms. Invertebrate is a term coined by Jean-Baptiste Lamarck to describe any animal without a spinal column. ... Orders See taxonomy Insects are invertebrates that are taxonomically referred to as the class Insecta. ... Divisions Green algae Chlorophyta Charophyta Land plants (embryophytes) Non-vascular plants (bryophytes) Marchantiophyta - liverworts Anthocerotophyta - hornworts Bryophyta - mosses Vascular plants (tracheophytes) †Rhyniophyta - rhyniophytes †Zosterophyllophyta - zosterophylls Lycopodiophyta - clubmosses †Trimerophytophyta - trimerophytes Equisetophyta - horsetails Pteridophyta - true ferns Psilotophyta - whisk ferns Ophioglossophyta - adderstongues Seed plants (spermatophytes) †Pteridospermatophyta - seed ferns Pinophyta - conifers Cycadophyta - cycads Ginkgophyta... It has been suggested that Yeast (baking) be merged into this article or section. ... Divisions Chytridiomycota Zygomycota Ascomycota Basidiomycota The Fungi (singular: fungus) are a large group of organisms ranked as a kingdom within the Domain Eukaryota. ...

Humans produce a little uric acid as a result of purine breakdown. Excess uric acid production can lead to a type of arthritis known as gout. Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... Arthritis (from Greek arthro-, joint + -itis, inflammation; plural: arthritides) is a group of conditions where there is damage caused to the joints of the body. ...

Urea is essentially a waste product, although it is used by the body during times of volume reduction. In the later portions of the kidney collecting tubule, urea is reintroduced into the kidney medulla to raise osmolality. Afterwards, water flowing through the collecting tubule follows back into the body by osmosis. The kidneys are bean-shaped excretory organs in vertebrates. ... Osmosis is the net movement of water through a selective permeable membrane from a region of low solute potential to a region of high solute potential (or equivalently, from a region of high solvent potential to a region of low solvent potential). ...

Urea is dissolved in blood (in humans in a concentration of 2.5 - 7.5 mmol/liter) and excreted by the kidney in the urine. The kidneys are bean-shaped excretory organs in vertebrates. ... To meet Wikipedias quality standards, this article or section may require cleanup. ...

In addition, a small amount of urea is excreted (along with sodium chloride and water) in human sweat. Sodium chloride, also known as common salt, table salt, or halite, is a chemical compound with the formula NaCl. ... SWEAT is an OLN/TSN show hosted by Julie Zwillich that aired in 2003-2004. ...

Commercial production

Urea is a nitrogen-containing chemical product which is produced on a scale of some 100,000,000 tonnes per year worldwide.

Urea is produced commercially from synthetic ammonia and carbon dioxide. Urea can be produced as prills, granules, flakes, pellets, crystals and solutions. Ammonia is a compound of nitrogen and hydrogen with the formula NH3. ... Carbon dioxide is a chemical compound composed of one carbon and two oxygen atoms. ... Prill is a dry pellet form of the explosive ANFO. Categories: Stub ... Granule is a generic term used for a small particle or grain. ...

More than 90% of world production is destined for use as a fertilizer. Urea has the highest nitrogen content of all solid nitrogeneous fertilizers in common use. (46.4%N.) It therefore has the lowest transportation costs per unit of nitrogen nutrient. spreading manure, an organic fertilizer Fertilizers (British English, also fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless Atomic mass 14. ... A nutrient is either element or compound necessary for or contributing to an organisms metabolism, growth, or other functioning. ...

Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g. in “foliar feed’ fertilizers. This article or section does not cite its references or sources. ... United American Nurses (UAN) is an American union affiliated with the American Nurses Association (ANA) and the AFL-CIO. Unlike other unions that some American nurses belong to, such as the Service Employees International Union, the UAN represents only registered nurses (RNs). ...

Solid urea is marketed as prills or granules. The advantage of prills is that in general they can be produced more cheaply than granules which, because of their narrower particle size distribution have an advantage over prills if applied mechanically to the soil. Properties such as impact strength, crushing strength and free-flowing behaviour are particularly important in product handling, storage and bulk transportation. Loess field in Germany Soil horizons are formed by combined biological, chemical and physical alterations. ...

Production

Urea is produced commercially from two raw materials, ammonia and carbon dioxide. Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum derived raw materials. This allows direct synthesis of urea from these raw materials.

The production of urea from ammonia and carbon dioxide takes place in an equilibrium reaction, with incomplete conversion of the reactants. The various urea processes are characterized by the conditions under which urea formation takes place and the way in which unconverted reactants are further processed.

Unconverted reactants can be used for the manufacture of other products, for example ammonium nitrate or sulphate, or they can be recycled for complete conversion to urea in a total-recycle process.

Two principal reactions take place in the formation of urea from ammonia and carbon dioxide. The first reaction (2NH₃ + CO₂ --> H₂N-CO-NH₃OH (ammonium carbamate)) is exothermic and the second reaction (H₂N-CO-NH₃OH (ammonium carbamate) --> H₂N-CO-NH₂ + H₂O) is endothermic. Both reactions combined are exothermic.

Industrial use

Urea's commercial uses include:

• As a raw material for the manufacture of plastics specifically, urea-formaldehyde resin.
• As a raw material for the manufacture of various glues (urea-formaldehyde or urea-melamine-formaldehyde). The latter is waterproof and is used for marine plywood.
• As a component of fertilizer and animal feed, providing a relatively cheap source of fixed nitrogen to promote growth.
• As an alternative to rock salt in the deicing of roadways and runways. It does not promote metal corrosion to the extent that salt does.
• As an additive ingredient in cigarettes, designed to enhance flavour.
• Sometimes used as a browning agent in factory-produced pretzels.
• As an ingredient in some hair conditioners, facial cleansers, bath oils and lotions.
• It is also used as a reactant in some ready-to-use cold compresses for first-aid use, due to the endothermic reaction it creates when mixed with water.
• Active ingredient for diesel engine exhaust treatment AdBlue and some other SCR systems.
• Used, along with salts, as a cloud seeding agent to expedite the condensation of water in clouds, producing precipitation.
• The ability of urea to form clathrates (also called host-guest complexes, inclusion compounds, and adducts) was used in the past to separate paraffins.
• As a flame-proofing agent.
• As a clean burning fuel for motor vehicles and stationary engines.
• As a NOx-reducing reactant in diesel exhaust.

Household items made out of plastic. ... A urea-formaldehyde resin is a transparent thermosetting resin made from urea and formaldehyde heated in the presence of such a mild base as ammonia or pyridine. ... spreading manure, an organic fertilizer Fertilizers (British English, also fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ... In agriculture, fodder or animal feed is any foodstuff that is used specifically to feed livestock, such as cattle, sheep, chickens and pigs. ... Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds useful for other chemical processes (such as, notably, ammonia, nitrate and nitrogen dioxide) [1]. Nitrogen fixation is performed naturally by a number of different prokaryotes... A lit cigarette will burn to ash from one end. ... This article is about flavor, the sensory impression. ... A pretzel is a baked snack that is ordinarily twisted into a unique knot-like shape. ... A reactant or reagent is any substance initially present in a chemical reaction. ... In thermodynamics, the word endothermic describes a process or reaction that absorbs energy in the form of heat. ... Water is an odourless substance that is essential to all known forms of life and is known as the universal solvent. ... AdBlue is a solution of urea in demineralised water (32. ... Cloud seeding, also known as weather modification, is the attempt to change the amount or type of precipitation that falls out of clouds, or their structure, by dispersing substances into the air which allow water droplets or ice crystals to form more easily. ... A clathrate or clathrate compound is a chemical substance consisting of a Greek klethra, meaning bars (in the sense of a lattice). ...

Laboratory use

Urea is a powerful protein denaturant. This property can be exploited to increase the solubility of some proteins. For this application it is used in concentrations up to 10 M. Urea is used to effectively disrupt the noncovalent bonds in proteins. Urea is an ingredient in the synthesis of urea nitrate. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Irreversible egg protein denaturation and loss of solubility, caused by the high temperature (while cooking it) In biochemistry, denaturation is a structural change in biomolecules such as nucleic acids and proteins, such that they are no longer in their native state, and their shape which allows for optimal activity. ... In chemistry, the molar volume of a substance is the ratio of the volume of a sample of that substance to the amount of substance (usually in mole) in the sample. ...

Medical use

Drug use

Urea is used in topical dermatological products to promote rehydration of the skin. If covered by an occlusive dressing, 40% urea preparations may also be used for nonsurgical debridement of nails. Dermatology (from Greek derma, skin) is a branch of medicine dealing with the skin and its appendages (hair, nails, sweat glands etc). ... In zootomy and dermatology, skin is an organ of the integumentary system made up of multiple layers of epithelial tissues that guard underlying muscles and organs. ... An occlusive dressing is an air- and water-tight trauma dressing used in first aid. ... Debridement is a medical term referring to the removal of dead, damaged, or infected tissue to improve the healing potential of the remaining healthy tissue. ... Long nails are sometimes seen on women in Western cultures as well as women and men in some Asian cultures. ...

Clinical diagnosis

See blood urea nitrogen ("BUN") for a commonly performed urea test, and marker of renal function. The blood urea nitrogen (BUN) test is a measure of the amount of nitrogen in the blood that comes from urea. ... In medicine (nephrology) renal function is an indication of the state of the kidney and its role in physiology. ...

Other diagnostic use

Isotopically-labeled urea (carbon 14 - radioactive, or carbon 13 - stable isotope) is used in the Urea breath test, which is used to detect the presence of Helicobacter pylori (H. pylori, a bacterium) in the stomach and duodenum of humans. The test detects the characteristic enzyme urease, produced by H. pylori, by a reaction that produces ammonia from urea. This increases the pH (reduces acidity) of the stomach environment around the bacteria. Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... Carbon-13 is a stable isotope of carbon. ... The urea breath test is a rapid diagnostic procedure used to identify infections by Helicobacter pylori, a spiral bacterium implicated in gastritis, gastric ulcer, and peptic ulcer disease. ... Binomial name Helicobacter pylori ((Marshall 1985) Goodwin 1989) Helicobacter pylori is a bacterium that infects the mucus lining of the stomach and duodenum. ...

Similar bacteria species to H. pylori can be identified by the same test in animals (apes, dogs, cats - including big cats).

Ureas

Ureas or carbamides are a class of chemical compounds sharing the same functional group RR'N-CO-NRR' based on a carbonyl group flanked by two organic amine residues. They can be accessed in the laboratory by reaction of phosgene with primary or secondary amines. Example of ureas are the compounds carbamide peroxide, allantoin and Hydantoin. Ureas are closely related to biurets and structurally related to amides, carbamates, diimides, carbodiimides and thiocarbamides. A chemical compound is a chemical substance consisting of two or more different chemically bonded chemical elements, with a fixed ratio determining the composition. ... In organic chemistry, functional groups are specific groups of atoms within molecules, that are responsible for the characteristic chemical reactions of those molecules. ... Carbonyl group In organic chemistry, a carbonyl group is a functional group composed of a carbon atom double-bonded to an oxygen atom. ... Phosgene (also known as carbonyl chloride, COCl2) is a highly toxic gas or refrigerated liquid that was used as a chemical weapon in World War I. It has no color, but is detectable in air by its odor, which resembles moldy hay. ... The general structure of an amine Amines are organic compounds and a type of functional group that contain nitrogen as the key atom. ... Carbamide peroxide is an oxidising agent, consisting of hydrogen peroxide compounded with urea. ... Allantoin is a botanical extract of the comfrey plant and is used for its healing, soothing, and anti-irritating properties. ... Hydantoin, which is also known as glycolylurea, is a heterocyclic organic compound which can be thought of as a cyclic double-condensation reaction product of glycolic acid and urea. ... Biuret is a chemical compound with the chemical formula C2O2N3H5. ... Amide functional group In chemistry, an amide is one of two kinds of compounds: - the organic functional group characterized by a carbonyl group (C=O) linked to a nitrogen atom (N), or a compound that contains this functional group (pictured to the right); or - a particular kind of nitrogen anion. ... Carbamates are a group of organic compounds sharing a common functional group with the general structure -NH(CO)O-. More precisely the carbamate group is considered an amide group with an alkoxy or hydroxy functional group next to the carbonyl group. ... In chemistry, azo compounds generally have a molecular formula of the form R-N=N-R, in which R and R can be either aromatic or aliphatic. ... A carbodiimide is a functional group consisting of the formula N=C=N. Carbodiimides hydrolyze to form ureas, which makes them rarely found in nature. ...

External links

• MSDS sheet on urea
• Use of urea in hand dyeing
• Urea: synonymes, CAS, formula
• U3K Energy: Patented technolgy for use of urea as fuel (not SCR additive) for internal combustion engines and fuel cells.

• Links to external chemical sources.