posted by Mercedes .
Why are combustion reactions always exothermic?
Is it just because it gives off heat?
Thanks ahead of time
Exothermic MEANS it gives off heat; therefore, I don't think that can be a reason. Think of wood burning. Magnesium strips burning. A wax cancle burning. Anything burning. The products of combustion, such as CO2 and H2O are so much more stable than the cellulose (of wood) or the reactive metals (such as Mg metal) or the wax (of candles) that you are always going from a high energy state to a low energy state and energy is always given off.