Name: Aliyana Campbell Date: July 10th, 2024 CHM-251: Organic Chemistry I Saponification Abstract Saponification is the process of making soap. It is one of the earliest examples of using organic chemistry to produce a man-made product. The purpose of this experiment is to create soap and to test its abilities as a surfactant and as an emulsifying agent. Background The formation of soap involves the reaction of triglycerides (natural fats and oils) with sodium or potassium hydroxide. The results should be sodium or potassium salts of fatty acids and glycerol. Soap is a surfactant and an emulsifying agent. A surfactant is a compound that reduces the surface tension when dissolved in water and aqueous solutions. Each surfactant molecule has a hydrophilic (polar) end and a hydrophobic (nonpolar) end. The polar end dissolves polar molecules and the nonpolar side dissolves nonpolar molecules. This ability also ties in with emulsification, which is the method of mixing two immiscible substances (i.e., polar and nonpolar). Materials & Methods Materials: Hotplate w/ magnetic stirrer 250 mL beaker Lard Ethanol 20% sodium hydroxide Dye (optional) Saturated sodium chloride Deionized water Test tubes Phenolphthalein Calcium chloride Magnesium chloride Silicon mold Methods: Saponification. Obtain a hotplate. Place 20 grams of animal fat (lard) and 20 mL of ethanol into a 250-mL beaker. Place the beaker on the hotplate and add 25 mL of 20% sodium hydroxide. Heat the mixture, using the magnetic stirrer, for at least 60 seconds. Turn off the stirrer, keeping the heat on. (Fragrances can be added at this point.) Continue to heat until the foam in the beaker reaches the halfway mark. No odor of ethanol should be present at this time – only the added fragrances, if any. Once the foam has reached halfway, turn off the heat and add 100 mL of saturated sodium chloride to the mixture. Stir the mixture for approximately 1 minute. At this point the soap will precipitate out of the mixture. Filter the soap through a suction funnel (vacuum filtration) and wash the soap in the funnel with two 10-mL portions of ice cold deionized water. Carefully transfer your soap into the silicon molds and leave it to harden. (It will probably take a couple of days to completely harden.) pH testing. Take 20 mL of deionized water into a clean container and add a small amount of the soap or soap residue to create a small soap-water mixture. Transfer about 2-3 mL of this soap-water mixture to a test tube and add a few drops of phenolphthalein. Observe and note any color changes. Hardness testing. Obtain two clean test tubes and label them A and B. Place another 2-3 mL of the soapwater mixture in each of these test tubes. Add an equal amount of calcium chloride to the test tube. Place an equal amount of calcium chloride in test tube A and mark any changes observed. Add an equal amount of magnesium chloride to test tube B and observe and mark any changes. Emulsification testing. Label two more test tubes #1 and #2 and place 2-3 mL of the soap-water mixture into each tube. Add a drop of distilled water (deionized water) to test tube #1 and a drop of olive oil to test tube #2. Shake both tubes vigorously and then observe the contents. Results pH results. The soap-water mixture turned magenta as soon as the phenolphthalein hit it. This indicated the high alkalinity (high pH) of the soap. Alkaline soap makes a better laundry detergent than it does a bathing soap. Hardness results. There was precipitate in both mixtures, but the precipitate was more concentrated in the magnesium chloride tube. Emulsification results. The precipitate in the olive oil tube was thicker than that in the water tube. The indicates minimal emulsification. Discussion The soap came out pretty well. I attempted using it to wash my hands and it did work pretty well. The soap itself smelled horrible, though. I guess we had failed to burn off all the ethanol before transferring it to the suction funnel. References