Answer to Question #198506 in General Chemistry for lea

Question

Urea (CH4N2O) is a common fertilizer that can be synthesized by the reaction of ammonia (NH3) with carbon dioxide as follows: 2NH3(aq)+CO2(aq)→CH4N2O(aq)+H2O(l) In an industrial synthesis of urea, a chemist combines 138.7 kg of ammonia with 211.4 kg of carbon dioxide and obtains 167.4 kg of urea.

Determine the theoretical yield of urea

Express your answer using four significant figures.

Answer 1

Theoretical yield of Urea can be calculated as

$\frac{(138.7 \; kg \; NH_3) }{ (17.04 \; g \;NH_3/mol)} = 8.1396 \;kmol \; NH_3 \\ \frac{(211.4 \;kg \;CO_2) }{ (44.01\; g \;CO_2/mol)} = 4.80345 \;kmol \;CO_2$

8.1396 kilomoles of NH₃ would react completely with 8.1396 $\times \frac{1}{2}$ = 4.06983 kilomoles of CO₂, but there is more CO₂ present than that, so CO₂ is in excess and NH₃ is the limiting reactant.

(8.1396 kmol NH₃) $\times$ (1 mol CH₄N₂O / 2 mol NH3) $\times$ (60.07 g/mol CH₄N₂O) = 244.47 kg CH₄N₂O in theory

Answer: Theoretical yield of Urea is 244.47 kg