Challenges we will face terraforming Mars

Because Mars has no atmosphere, astronauts will be exposed to high levels of cosmic radiation which could cause cancer or death. The lack of atmosphere also produces severe weather - very high and low temperature as well as very high wind speeds. Astronauts will likely have to live nearby caves or underground until an atmosphere can be formed due to these elements.

NH₃ is the limiting reactant.Theoretical yield = 120 kg% yield = 72.9 %

Explanation:

2NH₃ (aq) + CO₂ (aq) → CH₄N₂O (aq) + H₂O (l)

First we convert the given masses of reactants to moles, using their respective molar masses:

68.2 kg NH₃ ÷ 17 kg/kmol = 4.01 kmol NH₃105 kg CO₂ ÷ 44 kg/kmol = 2.39 kmol CO₂

2.39 kmol of CO₂ would react completely with (2.39 * 2) 4.78 kmol of NH₃. There are not as many NH₃ kmoles so NH₃ is the limiting reactant.

We calculate how much urea would form with a 100% yield, using the moles of limiting reactant:

4.01 kmol NH₃ * = 2.00 kmol CH₄N₂O

We convert that amount to kg:

2.00 kmol CH₄N₂O * 60 kg/kmol = 120 kg CH₄N₂O

Finally we calculate the percent yield:

87.5 kg / 120 kg * 100% = 72.9 %