What mass (in grams) of fluorine gas is needed to react completely with 17.8 g of elemental sulfur, S8, to form sulfur hexafluoride SF6?

Question

What mass (in grams) of fluorine gas is needed to react completely with

17.8 g of elemental sulfur, S8, to form sulfur hexafluoride SF6?

S8 (g) +24F2 (g) -> 8 SF6 (g)

Answer 1

Just like your last question, look at the balanced equation, USE MOLES, and then at the end, convert back to grams (in this question they specify grams, unlike in the last question where we left the answer in moles).

S₈(g) + 24F₂(g) ==> 8SF₆(g) ... balanced equation

17.8 g S₈ x 1 mol S₈ / 256.5 g = 0.06940 moles S₈

0.06940 mols S₈ x 24 mols F₂ / 1 mol S₈ = 1.666 moles F₂ needed

1.666 moles F₂ x 38.0 g / mol = 63.3 g F₂ needed