# How many moles of O_2 are required to generate 18 moles of H_2O in the reaction 2C_8H_18 + 25O_2 -> 16CO_2 + 18H_2O?

$18 m o l {H}_{2} O x \left(\frac{25 m o l {O}_{2}}{18 m o l {H}_{2} O}\right) = 25 m o l {O}_{2}$