CHEMICAL REACTIONS AND ENERGY CHANGES, EXOTHERMIC REACTIONS
CHEMICAL REACTIONS AND ENERGY CHANGES: During chemical reactions bond rearangement takes place. Bonds in the reactants must be broken first before new bonds in the products are formed. Bond breaking absorbeds energy whereas bond forming releases energy. Usually the total energy required to break the bonds is not the same as the energy released when the new bonds are formed. In some reactions energy absorbed from the surrounding is more and in some other reactions energy released by the system to the surrounding is more. Hence, chemical reactions are accompanied by energy exchange between the reacting system and the surrounding. This energy change of a chemical reactions is called enthalpy change of reaction and is represented by H. EXOTHERMIC REACTIONS: Reactants ...