E6: Saponification S.No. Name of the Experiment Date of conduction Date of Submission Team Members E5 Saponification 13/10/20 20/10/20 Oindrila Ghosh, Deepshika Dutta, Nishant Hinge, Aditya Goel AIM: Preparation of soap APPARATUS USED: 1.Round bottomed flask 2.Pipette 3.Test tube 4.Condenser 5.Measuring cylinder 6.Heating mantle 7.Weighing balance REAGENTS USED: 1.Soya oil or saturated triglyceride 2.Ethanol 3.Sodium hydroxide 4.Sodium chloride 5.Water THEORY 1.Saponification: Base hydrolysis of a fat or oil, resulting in the formation of a soap and an alcohol as a byproduct, is known as saponification. Saponification is used in the soap industry, in fire extinguishers, etc. 2.Fatty acid: There are around 20 naturally occurring fatty acids. Fatty acids are carboxylic acids with hydrocarbon chains of 4 - 36 carbon atoms. The even number of atoms is because fatty acids are naturally produced in cells by the polymerization of a 2 carbon acetate unit. Fatty acids may be saturated or unsaturated (containing double bonds). They may be plant based or of animal origin.
3.Vegetable oil: Vegetable oils are fatty acids obtained from plant based sources. Compared to animal based fatty acids, these are relatively more unsaturated and thus, are liquids. This is the reason why they are called oils instead of fats. Examples are coconut oil and linseed oil. 4.Animal fat: Animal fats are fatty acids obtained from animal based sources. Compared to plant based fats, these are more saturated and thus, are solids or semi-solids and hence, are called fats and not oils. Tallow from cattle and sheep is an example of this. 5.Soap: Soaps are generally sodium, potassium or lithium salts of long hydrocarbon chain carboxylic acids prepared using the saponification reaction. Based on the alkali used in the process, they can be hard soaps (sodium hydroxide used), soft soaps (potassium hydroxide used) or lithium soaps. Various kinds of soaps are available commercially: toilet soaps, bathing soaps, transparent soaps, medicinal soaps, etc. PROCEDURE:1.Place 4-5 drops of the saturated triglyceride in a 250 mL short-neck round-bottom flask. 2. Add 2 mL of a pre-made 1:1 water-ethanol mixture that contains 0.18 g of sodium hydroxide. 3. Place a water condenser on the flask. With a slow flow of water through the condenser, gentlyreflux the mixture on the heating mantle for 45 min, taking care not to boil away the ethanol.At the end of the reactionperiod, some of the soap will be precipitated. 4.In a 10 mL flask, place 3 mL of a premade solution containing 0.8 g of sodium chloride per 3mL of water. 5.Transfer the reaction mixture to the flask containing the aqueous solution. 6.Collect the precipitated soap on the funnel using a filter paper. 7.Test the soap by adding a very small piece (about 5-15 mg) to a reaction tube.