Are reduction/displacement reactions exothermic or endothermic? Ive asked this question many times, but get?
they can be either. If endo then you are adding energy to the reaction and producing products will higher energy than the reactants. If exo the opposite is true. In the exo case, many times you need to exceed the activation energy to start the reaction. Just mixing oxygen and hydrogen gases will not spontaneously produce water. you need a spark (activation energy) to begin the exothermic reaction.
