What determines the amount of chemical energy a substance has?

The chemical energy in a substance is determined by the potential energy of the bonds of the products formed when it reacts. This is because the energy released or absorbed when a chemical reaction takes place is determined by the difference of the potential energy in the bonds of the products compared to the potential energy of the bonds in the reactants. If the reactant bonds have more potential energy then energy is released but if the product bonds have more potential energy then energy is absorbed when the reaction occurs.