See Also

Urea

Urea is an organic compound Organic compound

An organic compound is any member of a large class of chemical compound [i]s whose molecule [i]s contain ... 

 of carbon Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

, nitrogen Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

, oxygen Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8. ... 

 and hydrogen Hydrogen

|- | Triple point [i] || 13.8033 K, 7.042 kPa ... 

, with the formula Chemical formula

A chemical formula is a concise way of expressing information about the atom [i]s that constitute a par ... 

 C Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

O Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8. ... 

N Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

2H Hydrogen

|- | Triple point [i] || 13.8033 K, 7.042 kPa ... 

4 or 2C Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

O Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8. ... 

. Urea is also known as carbamide, especially in the recommended International Non-proprietary Names in use in Europe. For example, the medicinal compound hydroxyurea is now hydroxycarbamide Hydroxyurea

Hydroxyurea or hydroxycarbamide, is an antineoplastic drug [i] used in hematological malignancies [i] ... 

. Other names include carbamide resin, isourea, carbonyl diamide, and carbonyldiamine.

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Timeline

1773   Hilaire Rouelle discovers urea

1828   Science History of science

Science [i] is a body of empirical [i] and theoretical [i] knowledge, produced by a ... 

: Friedrich Wöhler Friedrich Wöhler

Friedrich Whler was a German [i] chemist [i], best-known for his synthesis of urea [i], but als ... 

 synthesizes Urea, disproving a cornerstone of vitalism Vitalism

Vitalism, as defined by the Merriam-Webster dictionary, is ... 

.



Encyclopedia

>>>>
Urea
General
Systematic name IUPAC nomenclature

IUPAC nomenclature is a system of naming chemical compound [i]s and of describing the science of chemistry [i] ... 

Diaminomethanal
Other names ?
Molecular formula Chemical formula

A chemical formula is a concise way of expressing information about the atom [i]s that constitute a par ... 

2CO
SMILES Simplified molecular input line entry specification

The simplified molecular input line entry specification or SMILES is a specification for unambiguo... 

 
NCN
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 Water

Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

108 g/100 ml
167 g/100 ml
251 g/100 ml
400 g/100 ml
733 g/100 ml
Melting point 132.7 °C
decomposes
Boiling point n.a.
Acidity  0.18
Basicity  13.82
Chiral rotation [a]D  Not chiral
Viscosity Viscosity

Viscosity is a measure of the resistance of a fluid [i] to deform under shear stress [i]. ... 

? cP at ? °C
Critical relative humidity 81%
73%
Heat of solution in water -57,8 cal/g
Nitrogen content 46,6 %N
Structure
Molecular shape Orbital hybridisation

In chemistry [i], hybridisation or hybridization is the concept of mixing atomic orbital [i]s to f ... 

?
Coordination geometry trigonal planar
Crystal structure Crystal structure

In mineralogy [i] and crystallography [i], a crystal structure is a unique arrangement of atoms in a crystal [i] ... 

 
?
Dipole moment Dipole

Definition

In physics, there are two kinds of dipoles = double and polos = pivot).... 

? D
Hazards
MSDS Material safety data sheet

A material safety data sheet is a form containing data regarding the properties of a particular substanc... 

Main hazards ?
Flash point ? °C
R/S statement R: ? S: ?
RTECS number ?
Supplementary data page
Structure & properties n, er, etc.
Thermodynamic data Phase behaviour
Solid, liquid, gas
Spectral data UV Ultraviolet-visible spectroscopy

Ultraviolet-visible spectroscopy or ultraviolet-visible spectrophotometry involves the spectroscopy [i] ... 

, IR Infrared spectroscopy

Infrared spectroscopy is the subset of spectroscopy [i] that deals with the Infrared [i] part of the electromagnetic spectrum [i] ... 

, NMR NMR spectroscopy

Nuclear Magnetic Resonance Spectroscopy most commonly known as NMR Spectroscopy is the name given ... 

, MS Mass spectrometry

Mass spectrometry is an analytical technique used to measure the mass-to-charge ratio [i] of ion [i]s. ... 

Related compounds
Other anions ?
Other cations ?
Related ?  biuret Biuret

Biuret is a a condensation compound of urea [i], equivalent to two molecules of urea less one of ammonia ... 


triuret
thiourea Thiourea

Thiourea is an organic compound [i] of carbon [i], nitrogen [i], sulfur [i] and hydrogen [i], with the formula [i] ... 

 
Related compounds
?
Except where noted otherwise, data are given for
materials in their standard state Standard state

In chemistry [i], the standard state of a material is its state [i] at 1 bar [i]. ... 



Urea is an organic compound Organic compound

An organic compound is any member of a large class of chemical compound [i]s whose molecule [i]s contain ... 

 of carbon Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

, nitrogen Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

, oxygen Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8.... 

 and hydrogen Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

, with the formula Chemical formula

A chemical formula is a concise way of expressing information about the atom [i]s that constitute a par ... 

 C Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

O Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8.... 

N Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

2H Hydrogen

|-
| Triple point [i] || 13.8033 K, 7.042 kPa
... 

4 or 2C Carbon

Carbon is a chemical element [i] in the periodic table [i] that has the symbol [i] C' ... 

O Oxygen

Oxygen is a chemical element [i] with the chemical symbol O and atomic number [i] 8.... 

.

Urea is also known as carbamide, especially in the recommended International Non-proprietary Names in use in Europe. For example, the medicinal compound hydroxyurea is now hydroxycarbamide Hydroxyurea

Hydroxyurea or hydroxycarbamide, is an antineoplastic drug [i] used in hematological malignancies [i] ... 

. Other names include carbamide resin, isourea, carbonyl diamide, and carbonyldiamine.

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 Friedrich Wöhler

Friedrich Whler was a German [i] chemist [i], best-known for his synthesis of urea [i], but als ... 

, who prepared it by the reaction of potassium cyanate with ammonium sulfate Ammonium sulfate

Ammonium sulfate,2SO4, sometimes known as Mohr's Salt, is a chemical compound commonly used as a fertilizer [i] ... 

. Although Woehler was attempting to prepare ammonium cyanate, by forming urea, he inadvertently disproved vitalism Vitalism

Vitalism, as defined by the Merriam-Webster dictionary, is
... 

, the theory that the chemicals of living organisms are fundamentally different from inanimate matter, thus starting the discipline of organic chemistry Organic chemistry

Organic chemistry is a specific discipline within the subject of chemistry [i]. ... 

.

Physiology

The individual atoms of urea come from carbon dioxide Carbon dioxide

Carbon dioxide is a chemical compound [i] composed of one carbon [i] and two oxygen [i] atoms. ... 

, water, aspartate Aspartic acid

Aspartic acid , also known as aspartate, the name of its anion [i], is one of the 20 natural proteinogenic [i] ... 

 and ammonia Ammonia

Ammonia is a compound [i] of nitrogen [i] and hydrogen [i] with the formula [i] ... 

 in a metabolic pathway Metabolic pathway

In biochemistry [i], a metabolic [i] pathway is a series of chemical [i] react ... 

 known as the urea cycle Urea cycle

The urea cycle, also known as the ornithine cycle, is a cycle of biochemical [i] reac ... 

, an anabolic process. This expenditure of energy is necessary because ammonia, a common metabolic Metabolism

[i]s in [[life|living]... 

 waste product, is toxic and must be neutralized. Urea production occurs in the liver Liver

The liver is an organ [i] in vertebrate [i]s, including human [i]s. ... 

 and is under the regulatory control of N-acetylglutamate.

Most organism Organism

In biology [i] and ecology [i], an organism is a living [i] complex adaptive system [i] ... 

s have to deal with the excretion of nitrogen waste originating from protein Protein

Proteins are large organic compound [i]s made of amino acid [i]s arranged in a linear chain and joined b ... 

 and amino acid Amino acid

In chemistry [i], an amino acid is any molecule [i] that contains both amine [i] and carboxyl [i] functional group [i] ... 

 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 Uric acid

Uric acid is an organic compound [i] of carbon [i], nitrogen [i], oxygen [i] and hydrogen [i] with the f... 

. Generally, birds and saurian reptile Reptile

Reptiles are tetrapod [i]s and amniote [i]s, animals whose embryo [i]s are surrounded by an amniotic membrane [i] ... 

s excrete uric acid, while the remaining species, including mammals, excrete urea. Remarkably, tadpole Tadpole

A tadpole is a larval amphibian [i], the juvenile form of a frog [i], toad [i], newt [i], salamander [i] ... 

s excrete ammonia, and shift to urea production during metamorphosis Metamorphosis

Metamorphosis is a biological process [i] by which an animal [i] physically develops [i]... 

.

The urea is formed in the livers of mammals in a cyclic pathway, from the break down of ammonia Ammonia

Ammonia is a compound [i] of nitrogen [i] and hydrogen [i] with the formula [i] ... 

, , which was initially named the Krebs-Henseleit cycle after its discoverers, and later became known simply as the urea cycle Urea cycle

The urea cycle, also known as the ornithine cycle, is a cycle of biochemical [i] reac ... 

. This cycle was partially deduced by Krebs & Henseleit in 1932 and was clarified in the 1940s as the roles of citrulline Citrulline

The chemical compound [i] citrulline is an a-amino acid [i]. ... 

 and argininosuccinate Argininosuccinic acid

Arginosuccinic acid is a chemical compound [i] that belongs to the class of the amino acid [i]s. ... 

 as intermediates were understood.

In this cycle, amino groups donated by ammonia Ammonia

Ammonia is a compound [i] of nitrogen [i] and hydrogen [i] with the formula [i] ... 

 and L-aspartate Aspartic acid

Aspartic acid , also known as aspartate, the name of its anion [i], is one of the 20 natural proteinogenic [i] ... 

 are converted to urea, while L-ornithine Ornithine

Ornithine is an amino acid [i], whose structure is:
... 

, citrulline, L-arginino-succinate, and L-arginine Arginine

Arginine is an a-amino acid [i]. ... 

 act as intermediates.

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, insect Insect

Insects are invertebrate [i]s that are taxonomically [i] referred to as the class Inse ... 

s, plant Plant

Plants are a major group of living things [i] including familiar organism [i]s such as tree [i]s, flower [i] ... 

s, yeast Yeast

Yeasts are single-celled fungi [i], a few species of which are commonly used to leaven [i] ... 

, fungi Fungus

A fungus is a eukaryotic [i] organism [i] that digests its food [i] externally and absorbs th ... 

, and even microorganisms.

Humans produce a little uric acid as a result of purine Purine

Purine is a heterocyclic [i] aromatic [i] organic compound [i], consisting of a pyrimidine [i] ring fuse ... 

 breakdown. Excess uric acid production can lead to a type of arthritis known as gout Gout

Gout is a form of arthritis [i] caused by the accumulation of uric acid [i] crystals in joint [i]s. ... 

.

Urea is essentially a waste product; it has no physiological function. It is dissolved in blood and excreted by the kidney Kidney

The fishes are green yellow pink and red excretory [i] organ [i]s in vertebrate [i]s. ... 

 in the urine.

Many researchers used to believe that a small amount of urea was excreted in human sweat. However that was proved wrong when Dr. M. Falk determined at RC Institute that only sodium chloride Sodium chloride

Sodium chloride, also known as common salt, table salt, or halite [i], is a chemical compound [i] ... 

 and water are excreted from sweat.

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 Ammonia

Ammonia is a compound [i] of nitrogen [i] and hydrogen [i] with the formula [i] ... 

 and carbon dioxide Carbon dioxide

Carbon dioxide is a chemical compound [i] composed of one carbon [i] and two oxygen [i] atoms. ... 

. Urea can be produced as prills, granules, flakes, pellets, crystals and solutions.

More than 90% of world production is destined for use as a fertilizer Fertilizer

Fertilizers or fertilisers are compounds given to plant [i]s with the intention of promoting grow ... 

. Urea has the highest nitrogen Nitrogen

Nitrogen is a chemical element [i] which has the symbol N and atomic number [i] 7 in the periodic table [i] ... 

 content of all solid nitrogeneous fertilizers in common use. It therefore has the lowest transportation costs per unit of nitrogen nutrient Nutrient

A nutrient is any element or compound necessary for or contributing to an organism's metabolism [i], gro ... 

.

Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions , e.g. in “foliar feed’ fertilizers.

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 Soil

Soil is the collection of natural bodies that form in earthy material on the land surface.... 

. Properties such as impact strength, crushing strength and free-flowing behaviour are particularly important in product handling, storage and bulk transportation.

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 is exothermic and the second reaction is endothermic. Both reactions combined are exothermic.

Industrial use

Urea's commercial uses include:
  • As a raw material for the manufacture of plastic Plastic

    Plastic covers a range of synthetic or semisynthetic polymerization [i] products. ... 

    s specifically, urea-formaldehyde resin.
  • As a raw material for the manufacture of various glues . The latter is waterproof and is used for marine plywood.
  • As a component of fertilizer Fertilizer

    Fertilizers or fertilisers are compounds given to plant [i]s with the intention of promoting grow ... 

     and animal feed Fodder

    In agriculture [i], fodder or animal feed is any foodstuff [i] that is used specifically to f ... 

    , providing a relatively cheap source of fixed nitrogen Nitrogen fixation

    Nitrogen fixation is the process by which nitrogen [i] is taken from its relatively inert molecular form... 

     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 cigarette Cigarette

    A cigarette is a tobacco [i] product manufactured out of cured and finely cut tobacco leaves, which are ... 

    s, designed to enhance flavour.
  • Sometimes used as a browning agent in factory-produced pretzels Pretzel

    A pretzel is a baked snack [i] that is ordinarily twisted into a unique knot [i]-like shape. ... 

    .
  • 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 Water

    Water is a taste [i]less, odor [i]less substance that is essential to all known forms of life [i] and i ... 

    .
  • Active ingredient for diesel engine exhaust treatment AdBlue and some other SCR systems.
  • Used, along with salts, as a cloud seeding Cloud seeding

    Cloud [i] seeding, also known as weather [i] modification, is the attempt to change the amount or ... 

     agent to expedite the condensation of water in clouds, producing precipitation.
  • The ability of urea to form clathrates Clathrate compound

    A clathrate or clathrate compound or cage compound is a chemical [i] substance [i] consistin ... 

      was used in the past to separate paraffins.
  • As a flame-proofing agent.
  • As a clean burning fuel for motor vehicles and stationary engines.

Laboratory use

Urea is a powerful protein Protein

Proteins are large organic compound [i]s made of amino acid [i]s arranged in a linear chain and joined b ... 

 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.

Medical use

;Drug use
Urea is used in topical dermatological products to promote rehydration of the skin Skin

In zootomy [i] and dermatology [i], skin is an organ [i] of the integumentary system [i] made up ... 

. If covered by an occlusive dressing, 40% urea preparations may also be used for nonsurgical debridement of nails.

;Clinical diagnosis
See blood urea nitrogen  for a commonly performed urea test, and marker of renal function.

;Other diagnostic use
Isotopically-labeled urea is used in the Urea breath test, which is used to detect the presence of Helicobacter pylori Helicobacter pylori

Helicobacter pylori is a bacterium [i] that infects the mucus [i] lining of the human stomach [i]. ... 

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 of the stomach environment around the bacteria.

Similar bacteria species to H. pylori can be identified by the same test in animals .

Ureas

Ureas or carbamides are a class of chemical compounds sharing the same functional group Functional group

In organic chemistry [i] functional groups are specific groups of atom [i]s within molecule [i]s, that ... 

 RR'N-CO-NRR' based on a carbonyl Carbonyl

In organic chemistry [i], a carbonyl group is a functional group [i] composed of a carbon [i] atom [i] double-bonded [i]... 

 group flanked by two organic amine residues. They can be accessed in the laboratory by reaction of phosgene Phosgene

Phosgene is the chemical compound [i] with the formula COCl2. ... 

 with primary or secondary amine Amine

Amines are organic compound [i]s and a type of functional group [i] that contain nitrogen [i] as the key ... 

s. Example of ureas are the compounds carbamide peroxide Carbamide peroxide

Carbamide peroxide, also called urea peroxide, is an oxidising agent, consisting of hydrogen peroxide [i] ... 

, allantoin Allantoin

Allantoin is a botanical [i] of the comfrey [i] plant and is used for its hea ... 

 and Hydantoin Hydantoin

Hydantoin, which is also known as glycolylurea, is a heterocyclic [i] organic compound [i] which c... 

. Ureas are closely related to biuret Biuret

Biuret is a a condensation compound of urea [i], equivalent to two molecules of urea less one of ammonia ... 

s and structurally related to amide Amide

n chemistry [i], an amide is one of two kinds of compound [i]s:
... 

s, carbamate Carbamate

Carbamates or urethane [i]s are a group of organic compound [i]s sharing a common functional group [i] w ... 

s, diimide Azo compound

In chemistry [i], azo compounds generally have a molecular formula [i] of the form R-N=N-R', in which R ... 

s, carbodiimide Carbodiimide

A carbodiimide is a functional group [i] consisting of the formula N=C=N. ... 

s and thiocarbamides.

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