Question

From a molecular viewpoint, where does the energy absorbed in an endothermic chemical reaction go?

Answer 1

An endothermic reaction involves absorption of energy from surroundings.

When the energy of products is less than that of reactantsWhere the energy contained in the products is less than that in the reactants, energy is released, and the reaction is said to be exothermic. In endothermic reactions, the products have more energy than the reactants, so energy is absorbed from their environment.

Now in reactions bond are break and bonds are formed. Energy is required for breaking of bond and energy will released in formation of bond.

A system will always try to reach its lowest energy state, bonds will only form if they result in the overall energy of the atoms after bonding being lower than it was before bonding.

However before making of new bonds previous bond have to be broken, which will require energy. if more energy is required to break bonds within the reactants than is released by the formation of new bonds, the overall reaction is endothermic, because there is a net transfer of energy from the surroundings to the reactants.