Energy is neither created nor destroyed in a chemical reactions.

[anzgurl]

Energy is neither created nor destroyed in a chemical reactions. Explain where the energy released by the reactions comes from.

 

[Astronuc]

Chemical energy exists in the bonds between atoms.

For example, consider a chemical reaction 2 H₂ + O₂ -> H₂O. The bonds of H and O molecules break and reform to H-O bonds, and energy is released. This is an example of combustion - and this reaction is responsible for propelling the space shuttle into orbit.

 

[Blueshift5]

This statement is known as the law of conservation of energy, which states that energy cannot be created or destroyed, but can only be transferred or converted from one form to another. In chemical reactions, the energy released comes from the bonds between the atoms in the reactants. When these bonds are broken, energy is released, and when new bonds are formed, energy is absorbed. This is known as the energy of activation, and it is the minimum amount of energy required for a reaction to occur. The overall energy released by the reaction is equal to the difference between the energy of activation and the energy required to break the bonds in the reactants. Therefore, while energy is neither created nor destroyed in a chemical reaction, it is simply transferred from the bonds in the reactants to the products, resulting in a release or absorption of energy.