Carbamide is a popular name for the chemical substance urea, a metabolite that removes excess nitrogen excreted by the kidneys. It serves isocyanate as a valuable source of nitrogen for fertilizer. Its chemical formula is H2N-CO-NH2. Urea is colorless and odorless and in solution is chemically neutral. At one time it was believed that organic compounds could not be formed apart from living sources. However, chemist Friedrich Wohler disproved that by synthesizing urea in 1828 from completely inorganic compounds. Carbamide is fairly easy for an amateur scientist to prepare.
Review the chemical reaction. The equation is one molecule of silver isocyanate plus one molecule of ammonium chloride produces one molecule of carbamide plus one molecule of silver chloride, or in terms of the reaction sequence using chemical formulas:
The molecular weights of the component compounds are, respectively, 150, 54, 60, and 143.
Maximize yield and purity by using the correct amount of reactant chemicals. They should be used in equal percentage numbers of their molecular weights. Thus, if 10 percent of the molecular weight is used in grams, or 15.0 grams, for ammonium isocyanate, then 10 percent in grams of ammonium chloride should also be used, or 5.4 grams.