Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Just Part B Please plusminus Calculations Involving Consecutive Reactions Melami

ID: 821375 • Letter: J

Question

Just Part B Please

plusminus Calculations Involving Consecutive Reactions Melamine, C3N3(NH2)3, is used in adhesives and resins. It is manufactured in a two-step process in which urea, CO(NH2)2. is the sole starting material, isocyanic acid, HNCO, is an intermediate, and ammonia, NH3, and carbon dioxide, CO2, gases are byproducts. In the second step of this reaction, isocyanic acid reacts to form melamine and carbon dioxide: HNC0(I) rightarrow C3N3(NH2)3(I) + C02(g) Balance this reaction and enter the coefficients below. Enter the coefficients in order separated by commas (e.g., 1, 4, 5, where l indicates the lack of a coefficient). Thus, the two-step process can be written as CO(NH2)2(l) rightarrow HNCO(l) + NH3(g) 6HNC0 rightarrow C3N3(NH2)3(1) + 3C02(g) What mass of melamine, C3N3(NH2)3, will be obtained from 177.5kg of urea, CO(NH2)2, if the yield of the overall reaction is 76.0% ? Express your answer to three significant figures and include the appropriate units.

Explanation / Answer


CO(NH2)2 => HNCO + NH3

6 HNCO => C3N3(NH2)3 + 3 CO2


Moles of HNCO = Moles of urea = mass/molar mass of urea

= 177.5/60.06 = 2.9554 kmol


Moles of melamine = 1/6 x moles of HNCO

= 1/6 x 2.9544 = 0.49256 kmol


Theoretical yield = moles x molar mass of melamine

= 0.49256 x 126.12 = 62.122 kg


Actual yield = percent yield/100 x theoretical yield

= 76.0/100 x 62.122

= 47.2 kg