Step-by-step explanation:
C₂H₄ + 3 O₂ ——> 2 CO₂ + H₂O
According to the coefficients of the equation 1 mol of C₂H₄ will react with 3 moles of O₂. Then, the molar ratio between C₂H₄ and O₂ is 1 to 3. We can use that relationship to find the number of moles of oxygen that are needed to react with 5.75 moles of C₂H₄.
1 mol of C₂H₄ = 3 moles of O₂
moles of O₂ = 5.75 moles of C₂H₄ * 3 moles of O₂/(1 mol of C₂H₄)
moles of O₂ = 17.25 moles
One mol of a gas at STP always occupies 22.4 L. We can use that relationship to find the volume of oxygen.
1 mol of O₂ = 22.4 L
volume = 17.25 moles of O₂ * 22.4 L/(1 mol of O₂)
volume = 386.4 L
Answer: 386.4 L at STP is needed to react.