Saponification The process of making soap We require measuring cylinders, common salt, glass beakers, coconut oil, 20% NaOH solution, Bunsen burner, funnel, Measure 25 ml coconut oil into a measuring cylinder. Pour the oil into a glass beaker. Take another measuring cylinder and measure 30 ml 20% NaOH solution into it.
Pour it into the beaker containing coconut oil. Stir the mixture vigorously using a glass rod. Touch the beaker from outside.
It will be observed that the beaker is warm. This is due to the exothermic reaction between vegetable oil i.e. coconut oil and sodium hydroxide solution. Place the beaker on a Bunsen burner and heat it until the mixture becomes a whitish paste.
The mixture is made up of soap in suspension form and glycerol. Remove the beaker from the flame and allow it to cool. Dip a ring in the syrup and pour the syrup over the beaker.
Red litmus paper in the suspension formed. When dipped in the suspension, red litmus paper changes to blue colour. This shows that the soap solution is basic in nature. Dip a blue litmus paper in the suspension. The colour of blue litmus paper remains the same.
This shows that soap suspension is not acidic in nature. Add 15 grams of common salt into the suspension. Stir it well with a glass rod.
It is observed that the soap is precipitated out as a solid. Take a filter paper and fix it in a filter funnel and hold a glass rod over the funnel. Take the beaker containing soap and pour it over the glass rod and filter the mixture. Soap is left on the filter paper.
Take a filter paper and remove soap from the funnel using a spatula and place it on the filter paper. Dry the soap by pressing it with another filter paper. Cut it into the desired shape with a knife.
Soap is thus prepared.