Carbamide peroxide

Hydrogen peroxide - urea

Names
Other names Urea peroxide, percarbamide, UHP
Identifiers
CAS Number	124-43-6 Y
3D model (Jmol)	Interactive image
ChEBI	CHEBI:75178
ChemSpider	29034 Y
ECHA InfoCard	100.004.275
PubChem	31294
UNII	31PZ2VAU81 Y
InChI InChI=1S/CH4N2O.H2O2/c2-1(3)4;1-2/h(H4,2,3,4);1-2H Y Key: AQLJVWUFPCUVLO-UHFFFAOYSA-N Y
SMILES O=C(N)N.OO
Properties
Chemical formula	CH6N2O3
Molar mass	94.07 g·mol−1
Appearance	White solid
Melting point	75 to 91.5 °C (167.0 to 196.7 °F; 348.1 to 364.6 K) (decomposes)
Pharmacology
ATC code	D02AE01 (WHO)
Hazards
Safety data sheet	External MSDS
EU classification (DSD)	Explosive, C
Flash point	60 °C (140 °F; 333 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Y  (what is YN ?)
Infobox references

Hydrogen peroxide - urea is a solid composed of equal amounts of hydrogen peroxide and urea. This compound is a white crystalline solid, which dissolves in water to give free hydrogen peroxide. Often called carbamide peroxide in the dental applications, it is used as a source of hydrogen peroxide for bleaching, disinfection, and oxidation. Hydrogen peroxide - urea contains solid and water-free hydrogen peroxide, which offers a higher stability and better controllability than liquid hydrogen peroxide when used as oxidizing agent.

For the preparation of the compound urea (which is stable to oxidizing agents such as hydrogen peroxide) is dissolved in 30% hydrogen peroxide (molar ratio 2:3) at temperatures below 60 °C. On cooling, hydrogen peroxide - urea precipitates in the form of small platelets.

Determination of the hydrogen peroxide content by titration with potassium permanganate solution gives a value of 35.4% which corresponds to 97.8% of the theoretical maximum value. The remaining impurity consists of urea.

The adduct can be stabilized by adding about 1% sodium pyrophosphate, sodium hexametaphosphate, dihydroxybutanedioic acid or EDTANa₂, since these complex the catalytically active heavy metal ions.

Akin to water of crystallization, hydrogen peroxide cocrystallizes with urea with the stoichiometry of 1:1. The compound is simply produced (on a scale of several hundred tonnes a year) by the dissolution of urea in excess concentrated hydrogen peroxide solution, followed by crystallization. The laboratory synthesis is analogous.