The combustion reaction for this would be written as:
C4H10 + 13/2O2 = 4CO2 + 5H2O
We are given the amount of butane to be used in the reaction. This will be the starting point for our calculation. We also use the balanced reaction to relate the substances.
12.5 mol C4H10 ( 5 mol H2O / 1 mol C4H10 ) = 62.5 mol H2O produced
