In this study, the kinetics of hydrazodicarbonamide (HDCA) synthesis reaction were investigated. Hydrazodicarbonamide is prepared by reaction of urea and hydrazine in acidic medium. Synthesis of HDCA from urea and hydrazine is a two-step reaction. In the first step, semicarbazide is synthesized from the reaction of one mole of urea and one mole of hydrazine and in the second step, semicarbazide reacts with urea to produce hydrazodicarbonamide. By controlling the temperature and pH in the

more »

... n, hydrazine concentration and the amount of produced hydrazodicarbonamide were measured and using this data, reaction rate constants were calculated. Based on this study, it was found that the semicarbazide formation reaction from hydrazine is the ratelimiting step. The rate of semicarbazide synthesis is -r 1 = 0.1396[NH 2 NH 2 ] 0.5810 and the rate of hydrazodicarbonamide synthesis is -r 2 = 0.7715 [NH 2 NHCONH 2 ] 0.8430 .