Question

What mass of melamine, C3N3(NH2)3, will be obtained from 188.0 kg of urea, CO(NH2)2, if the yield of the overall reaction is 70.0 % ?

Answer 1

A yield of 70.0% from 188.0 kg of urea results in approximately 141.9 kg of melamine.

To find the mass of melamine (
`\(C_3N_3(NH_2)_3\)`) obtained from 188.0 kg of urea (
`\(CO(NH_2)_2\)`), we first recognize the balanced chemical equation for the reaction:

`\[ 6CO(NH_2)_2 \rightarrow C_3N_3(NH_2)_3 + 6H_2O \]`

The molar ratio between urea and melamine is 6:1. Calculate the moles of urea and use the given yield (70.0%) to find the actual moles of melamine produced. Convert this to mass using the molar mass of melamine.

`\[ \text{Moles of urea} = \frac{188.0 \, \text{kg}}{60.06 \, \text{g/mol}} \]`

`\[ \text{Actual moles of melamine} = 6 * \text{moles of urea} * 0.70 \]`

`\[ \text{Mass of melamine} = \text{Actual moles of melamine} * 126.12 \, \text{g/mol} \]`

After calculations, the mass of melamine obtained is approximately 141.9 kg.