To determine the mass of carbon dioxide that is produced from the reaction, we use the initial amount of the limiting reactant which is butene in this case. Also, from the relation of the substances in the reaction we can relate CO2 and the amount of the reactant. We calculate as follows:
moles C4H8 = 259.9 g C4H8 ( 1 mol C4H8 / 56.12 g C4H8 ) = 4.63 mol C4H8 moles CO2 = 4.63 mol C4H8 ( 4 mol CO2 / 1 mol C4H8 ) = 18.52 mol CO2 mass CO2 = 18.52 mol CO2 ( 44.01 g / 1 mol ) = 815.27 g CO2 produced