Chemical energy

Chemical energy is a form of potential energy that can be stored in the bonds of chemical compounds. This energy is released in a chemical reaction, often producing heat as a by-product (exothermic reaction). Chemical energy is the energy that powers life processes and chemical reactions. It is one of the many forms of energy that exist in the universe and is essential for life.

Overview

Chemical energy is stored in the bonds of atoms and molecules. It is released or absorbed in chemical reactions. The most common example of a chemical reaction is the process of combustion, where chemical energy in fuel is converted into heat. Other examples include the energy stored in foods (which is released when the food is metabolized), and the energy stored in a battery (which is released when the battery is used).

Chemical reactions and energy

In a chemical reaction, the breaking of bonds in reactants and the formation of bonds in products results in a change in energy. The energy change in a chemical reaction is due to the difference in the amounts of stored chemical energy between the products and the reactants. This change in energy is called the enthalpy change of the reaction.

Types of chemical reactions

Chemical reactions can be classified into two types based on the energy change that occurs:

• Exothermic reactions: These are reactions that release energy, usually in the form of heat. Combustion is a common example of an exothermic reaction.
• Endothermic reactions: These are reactions that absorb energy from their surroundings. The process of photosynthesis in plants is an example of an endothermic reaction.

Chemical energy in biology

In biology, chemical energy is fundamental to life processes. It is stored in the bonds of carbohydrates, proteins, and fats, which are broken down during metabolism to provide energy for the organism. The process of cellular respiration is a key example of the conversion of chemical energy in glucose into other forms of energy needed by cells.

See also

• Potential energy
• Kinetic energy
• Thermodynamics
• Conservation of energy