How can you determine if a reacition is exothermic?

Exothermic reaction normally gives out heat for completing the reaction. the burning of a candle or the condensation of water vapour to water are all exothermic reactions. The prefix "ex" at the begining refers to external or outside and normally these kind of reactions release heat at the end.During neutralization, when the acida and bases are combined, it releases heat and this kind of reaction is definitely exothermic reaction.The combustion of any kind of fuel is also exothermic reaction as it gives out heat at the end.Fossil fuel burnt in cars and engines are good examples.

What do you mean by that? like the contents? the thc level?