CASå?·:57-13-6 Urea for vehicles, agricultural urea, urea N46ï¼? When the temperature of urea is below 20 â?? and the relative humidity is below 70%, it will not only not absorb moisture, but also evaporate water and reduce its water content; When the temperature exceeds 20 â?? and the relative humidity is higher than 80%, it starts to absorb moisture, and becomes paste when it is serious. When the air is dried again, it will re agglomerate, which is only inferior to ammonium nitrate. When the urea aqueous solution is at 80 â??, hydrolysis and decomposition reactions will occur, forming ammonium carbamate, ammonia gas and carbon dioxide respectively. Under acid and alkaline conditions, urea will decompose faster when it is heated. Urea is easy to combine with straight chain carbohydrates to form crystalline additional compounds; It forms a variety of double salts with various inorganic compounds, such as Ca (NO3) 2 �· 4CO (NH2) 2, NH4Cl �· CO (NH2) 2, CaChemicalbookSO4 �· 4CO (NH2) 2, MgSO4 �· 4CO (NH2) 2 �· 3H2O, Mg (NO3) �· 4CO (NH2) 2 �· 2H2O, etc; It is easy to form urea phosphate, dicalcium phosphate and water with monocalcium phosphate, namely Ca (H2PO4) 2 �· H2O+CO (NH2) 2 â?? H3PO4 �· CO (NH2) 2+CaHPO4+H2O; With nitric acid, it is easy to form urea nitrate, CO (NH2) 2+HNO3 â?? CO (NH2) 2 �· HNO3, which combines and relaxes the two; It can combine with formaldehyde to form urea formaldehyde compounds (uric acid rubber shrinks), in which the higher proportion of formaldehyde is urea resin, and the lower proportion is slow-release (effective) urea.