Question

What mass of melamine, C3N3(NH2)3, will be obtained from 137.0kg of urea, CO(NH2)2, if the yield of the overall reaction is 77.0% ?
Express your answer to three significant figures and include the appropriate units.

Answer 1

6 (NH₂)₂CO → C₃H₆N₆ + 6 NH₃ + 3 CO₂
M(urea) = 60 kmoles/kg
From 6 x 60 kg of urea it is produced 126 kg of melamine;
From 137.0 kg – X kg
X = 47.95 kg (of melamine)
If the yield is 77% so the mass of melamine will be 47.95 x 0.77 = 36.9215kg
Answer: ~36.922 kg