reacting 3 mol C4H10 and 12 mol O2 will occur as a complete combustion, true or false
2C4H10 + 13O2 ==> 8CO2 + 10H2O
How much CO2 will you get from 3 mols C4H10. That's 3 x (8/2) = 12.
How much CO2 will you get from 12 mols O2? That's 12 x (8/13) - 7.4
The answers are different so you will have some C4H10 left over. All of the O2 will be used.