Answer:
Theoretical yield is 138.4 g
Explanation:
In the first step we determine the reaction:
3Mg + N₂ → Mg₃N₂
Mass of reactant is 100 g. We assume the nitrogen is in excess, so we work with Mg. We convert mass to moles:
100 g . 1mol/ 24.3g = 4.11 moles of Mg.
Ratio is 3:1. 3 moles of Mg can produce 1 mol of nitride
Our 4.11 moles, may produce (4.11 . 1)/3 = 1.37 moles of Mg₃N₂
We convert mass to moles, to find the theoretical yield:
1.37 mol . 100.9 g/mol = 138.2 g