How much oxygen is produced in moles

Question

In the equation 2 C8H18 + 25O2 -> 18 H2O + 16 CO2 If 8 moles of hydrocarbon reacts how many moles of oxygen are needed

Answer 1

25 moles of O₂

= 8 moles of C₈H₁₈ x ——————— = 100 mol of O₂

2 moles of C₈H₁₈

Given moles of hydrocarbon need to be multiplied with the mole ratio of O₂ with C₈H₁₈ from the balanced chemical equation.