Chemistry is a discipline of physical sciences dealing with the matter and its properties. Matter starts its existence from sub-atomic particles up to large and heavy macromolecules. Chemistry deals with elements and their chemical properties studied through chemical reactions. Chemistry has three branches namely organic, inorganic and physical chemistry. Chemical reactions are of two types namely exothermic and endothermic. Exothermic reactions are the reactions in which heat energy is liberated whereas endothermic reactions are those in which heat energy is absorbed.