How many grams of zns are required to react with 12.6 l of oxygen gas at stp?

The balanced chemical equation:

2 ZnS + 3 O₂ → 2 ZnO + 2 SO₂

1 mole of any gas at STP occupies 22.4 L

? mole of O₂ gas at STP will occupy 12.6 L

we have 0.5625 mole of O₂

From the balanced equation we see that:

2 moles of ZnS react with 3 moles O₂

? mole ZnS react with 0.5625 mole O₂

Number of moles of ZnS = 0.375 mol

mass of ZnS = 0.375 * 97.45 (Molar mass) = 36.5 g ZnS