Why is heat evolved during an exothermic reaction?
Answers
because of releasing of any gas from the reaction....
Note: A Chemical Bond is a force of attraction that keeps atoms in a molecule together.
This answer is lengthy but perfect. Hope it helps!
Explanation:
An exothermic reaction is a type of reaction in which heat is evolved. In a chemical reaction, the chemical bond between the reactants ( substances that react with each other) breaks. This requires energy that is given by heat or other sources of energy. Then, new bonds are formed to produce new substances with entirely different properties and composition that are called products. As energy can neither be created nor be destroyed ( Law of conservation of energy), it is released during the new bond formation.
This makes a point of difference between exothermic reaction and endothermic reaction.
In an exothermic reaction, the energy released during the new bond formation is more than the energy used to break old bonds. This causes
rise in temperature.
In an endothermic reaction, the energy used to break the old bonds between the reactants is more than the energy released during the formation of new bonds. This caused fall in temperature.