How many moles of O2 are required if 12 moles of CuFeS2 are consumed

Question

2CuFeS₂ + 5O₂ -> 2Cu + 2FeO + 4 SO₂

Answer 1

The mole ratio of CuFeS₂ to O₂ from the balance equation is 2:5

12 moles of CuFeS₂ x (5 moles O₂ / 2 moles of CuFeS₂ ) = 30 moles of O₂