The combustion of 1 mole of co according to the reaction co(g) + ½o2(g) → co2(g) + 67.6 kcal gives off how much heat?

-67.6 kcal
-1,514 kcal
-33.3 kcal
-135.2 kcal
-none of the above

Combustion usually occurs when a hydrocarbon reacts with oxygen to produce carbon dioxide and water. Combustion reactions are almost always exothermic CO(g) + ½O2(g) → CO2(g) + 67.6 kcal 
base from the reaction, the stoichiometric ratio is 1 mole CO produce 67.6 kcal so the anwer is - 67.6 kcal because is it exothermic