How many moles of aluminum fluoride are made from this synthesis reaction?

Question

How many moles of aluminum fluoride (AlF3) will be made from the synthesis reaction of solid aluminum and 34.78g fluorine gas?

Answer 1

First the balanced reaction to get correct mole ratios: 2 Al + 3 F₂ --> 2 AlF₃. Then

(34.78 g F₂) * (1 mol F₂ / 37.996 g F₂) * (2 mol AlF₃ / 3 mol F₂) = 0.6102 mole AlF₃.