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Exothermic Reactions

By Janice VanCleave

Exothermic ReactionAn exothermic reaction is a chemical reaction that releases energy, such as heat, light, and/or sound.

This type of reaction occurs when the energy needed to cause the reaction is less than the energy needed to form the reactants.For example, burning is the combination of oxygen with a substance, such as the chemicals in a candle. Energy (in) is needed to melt the wax, and then break the chemical bonds of the reacting chemicals (wax and oxygen).

Activation Energy is an input  energy from the burning wick needed to break the bonds holding the wax atoms together as well as the energy holding the atoms of oxygen together.

Bond Energy Stored- This is an input energy stored in the chemical bonds of the products.

Bond Energy Released- This is an output energy that is released when the bonds of the reactant chemicals are broken.

In an exothermic chemical reaction, the output energy is greater than the input energy.

When a candle burns, you see the colored flame (light energy) and feel the heat of the flame (heat energy).

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Filed Under: Chemistry Tagged With: exothermic reaction

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