Soap is a salt of fatty acids and it's chemical formula is RCOO-Na+, where R denotes any long chain alkyl group having 12 to 18 carbon atoms. The saponification reaction is exothermic in nature. In saponification reaction, the reaction mixture is basic in nature before the reaction, and can be basic after the reaction if NaOH is taken in excess. Saponification reaction is not a neutralisation reaction. It does not involve formation of water molecule. Hence, the correct option is D.