Urea Formula
The chemical formula CO(NH2)2 represents urea. In this compound one carbon atom, two nitrogen atoms (−NH2), and two amine groups (C=O) are attached.
Physical properties
Appearance: White crystalline solid at ordinary temperatures.
Odor: Odorless.
Solubility: Very soluble in water, dissolves to colorless and clear solution; soluble in alcohol and somewhat soluble in acetone.
Melting point: The urea melting point is about 132.7 °C or 271°F.
Boiling point: Urea does not have a well-defined boiling point as it decomposes before reaching its boiling point and degrades into ammonia and carbon dioxide at temperatures above 135°C (275°F).
Density: The density of solid urea is about 1.32 g/cm³.
Refractive index: The refractive index for urea is approximately 1.53.
Hygroscopicity: Urea is hygroscopic; that is, it may absorb moisture from the air.
Chemical properties
Hydrolysis: Urea hydrolysis in the presence of water, especially under the action of the enzyme urease, to form ammonia and carbon dioxide.
CO(NH2)2+H2O→2NH3+CO2
This reaction is useful in the production of ammonia and as a nitrogen source in soil.
Decomposition of Urea: Urea upon heating produces ammonia and carbon dioxide. It starts at a temperature higher than 135°C though, but its usage is common in industry.
CO(NH2)2→NH3+CO2
Formation of Biuret: The presence of base upon heating can lead to the formation of biuret with urea. The reaction can be utilized in the testing for the presence of urea.
2CO(NH2)2→NH2CONH(CONH2)+NH3
Reaction with acids: Reactions of urea with acids can lead to the production of an ammonium salt. As an example, the reaction of urea with hydrochloric acid occurs with the production of ammonium chloride and carbon dioxide
CO(NH2)2+2HCl→NH4Cl+CO2
Formaldehyde reaction: Urea reacts with formaldehyde to give urea-formaldehyde resins, used in adhesives, coatings, and molded objects.
CO(NH2)2+CH2O→Urea-formaldehyde resin
Polymerization: Urea can polymerize to give urea-formaldehyde polymers, used in several industrial applications, including adhesives and the production of laminated plastics.
Reaction with Hypochlorites: Urea reacts with hypochlorites as sodium hypochlorite to yield nitrogen trichloride and other by-products. This reaction usually finds its application in chemical synthesis.
CO(NH2)2+3NaOCl→NCl3+Na2CO3+2NaCl+H2O
Applications of Urea
Fertilizers: Among the nitrogen fertilizers, urea is the most widely used. This fertilizer contains a very high nitrogen percentage and is highly important in the development of plants. Applications include broadcasting on the ground or incorporation into liquid formulations.
Animal feed additive: Urea is added to animal feeds to provide a source of non-protein nitrogen, especially to ruminant animals such as cattle. This helps in improving the protein value of the feeds.
Resins: Urea is used in the production of urea-formaldehyde resins for adhesives, and surface coatings, and in the processing of molded plastics and laminates.
Synthesis: Urea is a starting material in the synthesis of more sophisticated chemicals such as biuret, ammonium carbonate, and isocyanates.
Medical Applications: Urea is used in some pharmaceutical manufacturing processes. Topical creams and ointments, in treating skin conditions such as psoriasis and eczema, for example, depend on the use of urea.
Dialysis: It is employed in medical dialysis solutions to assist in the removal of urea, along with other waste products, from the blood of patients who have renal failure.
Industrial Uses: De-icing and Anti-icing: Urea is applied as a de-icing material in road systems and aircraft runways. It contributes to lowering the freezing point of water and is less corrosive compared to conventional salts.
Water treatment: Urea is applied to water treatment processes to control and reduce nitrogen levels.
Cosmetics: Urea is used in a lot of skincare products due to its moisturizing effect. It helps in keeping moisture and improving skin texture.
Textiles- dye fixative: Urea finds usage in textiles for aiding dyeing and improving color fastness.
Chemical reagent: Urea is employed as a chemical reagent in many kinds of chemical testing and investigation in fields like protein studies or enzyme assays.
It is these applications that make urea a useful compound in industries such as agriculture, manufacturing, pharmaceuticals, and environmental management.