Answer:
Yield = 66.7%
Explanation:
4P + 5O₂ → 2P₂O₅
P: 31 g/mol
O₂: 32 g/mol
P₂O₅: 142 g/mol
31 g P ____ 1 mol
2.80 g P __ x
x = 0.09 mol P
142 g P₂O₅ ____ 1 mol
3.89 g P₂O₅ ___ y
y = 0.03 mol P₂O₅
In a 100% yield, 4 mol of P produces 2 mol of P₂O₅. 0.09 of P should, therefore, produce 0.045 mol of P₂O₅.
Yield = (0.03 mol / 0.045 mol) x 100
Yield = 66.7%