Answer:
50
Step-by-step explanation:
To find the number of moles of O2 needed to react fully with 4 moles of octane (C8H18), we need to balance the equation first:
2 C8H18 + 25 O2 -> 16 CO2 + 18 H2O
So, the balanced equation tells us that for every 2 moles of C8H18, 25 moles of O2 are needed. Thus, to react with 4 moles of C8H18, we need 25 * (4/2) = 50 moles of O2.