Molar Mass of Urea (CH₄N₂O)

Each row shows how much mass one element contributes to the total for CH₄N₂O.

Save a printable summary, revision sheet, practice worksheet, or laboratory reference for Urea (CH₄N₂O).

Without looking above, write the atom count for CH₄N₂O, then compute the molar mass. Check your answer against 60.056 g/mol.

Next challenge: how many grams are in 0.250 mol of Urea? Multiply 0.250 × 60.056 to get 15.014 g.

Ammonia volatilization from applied urea fertilizer contributes to air quality and nitrogen deposition concerns; excess agricultural nitrogen runoff can contribute to waterway eutrophication.

The primary nitrogenous waste product of mammalian protein metabolism, synthesized via the liver's urea cycle and excreted in urine; blood urea nitrogen is a standard clinical kidney function marker.

Preparation and production

Industrially synthesized by reacting ammonia with carbon dioxide under high pressure and temperature to form ammonium carbamate, which then dehydrates to urea: 2 NH₃ + CO₂ → NH₂COONH₄ → CO(NH₂)₂ + H₂O. This is known as the Bosch–Meiser urea process, closely linked to the Haber–Bosch ammonia synthesis that supplies its nitrogen feedstock.

Global urea production exceeds 180 million tonnes annually, making it the highest-volume manufactured nitrogen compound, overwhelmingly destined for agricultural fertilizer use.

Urea was first isolated from urine by Hilaire Rouelle in 1773, but its true chemical significance emerged in 1828 when Friedrich Wöhler synthesized it by heating ammonium cyanate, an inorganic salt — a discovery credited with undermining vitalism and helping establish organic chemistry as a discipline governed by the same physical laws as inorganic chemistry. Hans Krebs and Kurt Henseleit elucidated the biological urea cycle in 1932, and industrial urea synthesis from ammonia and CO₂ (the Bosch–Meiser process) was developed in the early 20th century alongside the broader growth of the nitrogen fertilizer industry.

Hilaire Rouelle isolated urea from urine in 1773; Friedrich Wöhler achieved its landmark inorganic-to-organic synthesis in 1828.

Interesting facts

• Urea's 1828 synthesis by Friedrich Wöhler is widely taught as the experiment that helped end the doctrine of vitalism in chemistry.
• Urea has the highest nitrogen content by mass (46%) of any commonly used solid nitrogen fertilizer.
• The human body produces roughly 25–30 grams of urea daily as a byproduct of normal protein metabolism, excreted primarily through urine.
• Diesel exhaust fluid, essentially a purified urea solution, has become a common sight at fuel stations as more vehicles adopt selective catalytic reduction emissions technology.

Comparison with similar compounds

Urea (CH₄N₂O, 60.06 g/mol, 46% nitrogen by mass) has a substantially higher nitrogen content than ammonium nitrate (NH₄NO₃, 80.04 g/mol, 35% nitrogen), explaining urea's dominance in bulk nitrogen fertilizer markets despite ammonium nitrate's faster initial nitrogen release.

Store in a dry, sealed container, as urea is hygroscopic and can cake or degrade with moisture absorption. Keep away from strong oxidizers and avoid prolonged storage above its melting point, which can promote biuret formation.

Low acute hazard; treat as a mild irritant. Standard gloves and eye protection are sufficient for typical laboratory or agricultural handling. Avoid inhaling fine fertilizer-grade dust in bulk handling situations.

Low toxicity; generally recognized as safe in food-grade and pharmaceutical contexts at appropriate concentrations. Fertilizer-grade dust may cause mild respiratory or eye irritation.

• Mild eye and respiratory irritation from dust
• Ammonia release possible on prolonged heating or microbial decomposition
• Environmental nitrogen loading concerns with excessive agricultural application

Classification: Not classified as hazardous under GHS for standard fertilizer or laboratory-grade material

1. 1. Calculate the molar mass of urea (CH₄N₂O).

   Show answer

   12.01 + 4(1.008) + 2(14.01) + 16.00 = 60.06 g/mol

2. 2. What is the percent nitrogen by mass in urea?

   Show answer

   (2 × 14.01) / 60.06 × 100 = 46.6%

3. 3. How many moles of ammonia are released from complete hydrolysis of 30.03 g of urea?

   Show answer

   30.03 g ÷ 60.06 g/mol = 0.500 mol urea → 0.500 × 2 = 1.00 mol NH₃

4. 4. Why is the Wöhler synthesis considered a landmark event in the history of chemistry?

   Show answer

   It demonstrated that an organic compound (urea) could be synthesized from inorganic starting materials (ammonium cyanate), challenging vitalism and helping unify organic and inorganic chemistry under the same natural laws.

• Carbon DioxideCO₂
• AmmoniaNH₃

The sections above give the number you need for calculations. Here we look more closely at how Urea (CH₄N₂O) behaves chemically—so the molar mass connects to real reactions, properties, and laboratory practice.

Urea (CH₄N₂O, more descriptively written CO(NH₂)₂) is a simple organic compound with molar mass 60.06 g/mol (C 12.01 + H 4 × 1.008 + N 2 × 14.01 + O 16.00), consisting of a carbonyl group flanked by two amine groups. It holds a unique place in the history of chemistry as the first organic compound ever synthesized from inorganic starting materials, a landmark 1828 achievement by Friedrich Wöhler that helped dismantle the doctrine of vitalism — the belief that organic compounds could only be produced by living organisms through some special "vital force."

Biologically, urea is the primary nitrogenous waste product of protein and amino acid metabolism in mammals, produced in the liver through the urea cycle, which safely converts toxic ammonia (a byproduct of amino acid breakdown) into the far less toxic, highly water-soluble urea for excretion in urine. This detoxification pathway is so central to nitrogen metabolism that blood urea nitrogen (BUN) is a standard clinical marker of kidney function, since impaired renal filtration causes urea to accumulate in the bloodstream.

Industrially, urea is overwhelmingly the world's most widely used nitrogen fertilizer, prized for its high nitrogen content (46% by mass, the highest of any solid nitrogen fertilizer) and relatively low cost of production from ammonia and carbon dioxide. Beyond agriculture, urea serves as a key feedstock for urea-formaldehyde resins used in adhesives and particleboard, as the active reducing agent in diesel exhaust fluid (AdBlue) that helps catalytically reduce nitrogen oxide emissions, and in a striking twist of chemical history, as the compound whose accidental overheating with ammonium cyanate first revealed the biuret side reaction that still bears practical relevance in fertilizer quality control today.

CH₄N₂O, more informatively written CO(NH₂)₂, contains a central carbon double-bonded to oxygen (carbonyl) and single-bonded to two amine (–NH₂) groups. This arrangement makes urea the diamide of carbonic acid, structurally bridging simple carbonyl chemistry and amine/amide functionality, and gives the molecule strong hydrogen-bonding capacity despite its small size.

Urea is a weakly basic compound (due to its amide nitrogen lone pairs, though far weaker than a simple amine) and undergoes hydrolysis, especially enzymatically via urease, to ammonia and carbon dioxide — the reaction exploited by soil bacteria to release plant-available nitrogen from urea fertilizer. On heating above its melting point, urea can decompose to biuret and ammonia, and at higher temperatures further condenses to cyanuric acid and other products; controlling these side reactions is important in fertilizer manufacturing and quality.

Recalculate any formula with the molar mass calculator, compare atoms on the periodic table, or browse more compounds in the organic library.

• PubChem CID 1176: Urea compound data
• NIST Chemistry WebBook: Thermodynamic properties
• FAO: Global nitrogen fertilizer production and use statistics