Question

What mass of melamine, C3N3 (NH2)3, will be obtained from 101.5 kg of urea, CO (NH2)2, if the yield of the overall

reaction is 83.0 % ?
Express your answer to three significant figures and include the appropriate units.
View Available Hint(s)
Hint 1. How to approach the problem
To find the mass of melamine from the percentage yield you will first calculate its actual yield. Actual yield can
be calculated from the theoretical yield using the formula
percent yield
=
actual yield
theoretical yield
× 100%

Answer 1

The mass of melamine obtained from 178.5 kg of urea with an 83% yield is 187.51 kg.

To find the mass of melamine,
`C_3N_3(NH_2)_3`, obtained from 178.5 kg of urea,
`Co(NH_2)_2`, we need to consider the stoichiometry of the reaction and the yield.

First, let's write the balanced equation for the reaction between urea and melamine:

`2Co(NH_2)_2 + 3N_2H_4 \rightarrow C_3N_3(NH_2)_3 + 4NH_3`

From the balanced equation, we can see that 2 moles of urea react to produce 1 mole of melamine. Therefore, the molar ratio is 2:1.

Now, let's calculate the number of moles of urea:

178.5 kg × (1 mol/60.06 g) = 2973.93 mol

Since the molar ratio is 2:1, the number of moles of melamine produced is 1486.96 mol.

Finally, we can calculate the mass of melamine:

Mass of melamine = 1486.96 mol × 126.12 g/mol = 187506.91 g

Converting grams to kilograms, we get:

Mass of melamine = 187506.91 g × (1 kg/1000 g) = 187.51 kg

Complete question:

What mass of melamine,
`C_3N_3(NH_2)_3` will be obtained from 178.5 kg of urea,
`Co(NH_2)_2` if the yield overall reaction is 83% ?? Enter your answer numerically in kilograms.