I am having trouble understanding this.. If reactions are spontaneous when they create more entropy (disorder), why is it that most spontaneous reactions are exothermic? Such as an exothermic reaction like A + B ---> AB + Energy, AB then has lower energy than the reactants, which also means it is more stable in that form. If it is more stable, doesn't that mean it should have more order (less entropy)? Also wouldn't the molecule AB have less microstates than A + B, and thus less entropy? A + B atoms would have a lot more different positions than the AB molecule by itself. Even though I know it is wrong, it seems like endothermic reactions should be spontaneous since AB + Energy---> A + B would make the atoms less stable and give them more microstates. What am I missing?