Chemical reactions involve the making and breaking of chemical bonds (ionic and covalent) and the chemical energy of a system is the energy released or absorbed due to the making and breaking of these bonds. Breaking bonds requires energy, forming bonds releases energy, and the overall reaction can be either endergonic (\(\Delta G<0\)) or exergonic (\(\Delta G > 0\)) based on the overall changes in stability from reactants to products.
Simply put, chemical energy is the potential of a chemical system to undergo a transformation from one system to another and to impart a transformation on another system (this may be chemical, but can also involve other energy-requiring processes like electron current or pressure-volume work). Chemical energy is a concept that is related to every single process of life on earth and powers the cars that we drive.
Chemical energy plays a crucial role into each and every one of our every day lives. Through simple reactions and redox chemistry, the breaking and forming of bonds, energy can be extracted and harnessed into a usable fashion.
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