stociometry calculate moles

Question

Starting with the following equation, Fe₂O₃(s) + Al(s) → Fe(l) + Al₂O₃(s) calculate the moles of Fe₂O₃ that will be required to produce 645 grams of Fe.

Answer 1

Balanced equation

Fe₂O₃(s) + 2 Al(s) → 2 Fe(l) + Al₂O₃(s)

Moles of Fe = mass / molar mass = 645 g / 55.85 g/mol = 11.5 moles

Fe₂O₃ : Fe ratio = 1: 2

Moles of Fe₂O₃ = 11.5 / 2 = 5.75 moles