Saponification - Lab report PDF

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Experiment 9 Saponification 4/17/18

Purpose The purpose of this experiment is to create a soap from a commercial oil by performing a saponification reaction.The emulsifying properties of the soap will be tested. Introduction Saponification is the alkaline hydrolysis of a fat or oil which leads to the formation of soap. In order for saponification to work, the three ester bonds in the triglyceride (oil or fat) must be

broken using heat exposure under basic conditions. A carboxylic acid and alcohol will be formed from the bond breaking. Lastly, a carboxylic acid is deprotonated therefore, the negative charge on the oxygen will be attracted to positively charged ions in the sodium solution, which results in a soap. Procedure 1. 2. 3. 4. 5. 6. 7. 8. 9.

Turn on sand bath Add 2.5mL of deionized water and 2.5mL of ethanol to 15 mL round bottom flask Add 0.7 grams of sodium hydroxide to flask Add 1 mL of grape seed oil and boiling chips, reflux for 45 minutes. Let cool Add 4.0 grams of sodium chloride to 10 mL of water and dissolve Add hot reflux mixture to sodium solution. Vacuum filtrate to collect soap Add a small pellet of soap to 1.5 mL of ethanol in a test tube then adding two drops of phenolphthalein. Observe reaction 10. Dissolve 0.35 g of soap in 25 mL of distilled water 11. Add 2.5 mL of solution in 2 clean test tube and shake 12. Add 3 drops of 5% calcium chloride to one tube. Observe 13. Add 3 drops of 5% magnesium chloride to the other tube. Observe 14. Add 0.3g of sodium carbonate to the soap test tube 15. Fill tube with detergent and repeat steps 11-13. 16. Add 2 drops of oil into 3 clean test tubes 17. Add distilled water,soap,and detergent between the 3 tubes . Observe. 18. Add sulfuric acid to the remaining soap solution until it turns acidic (pH 1) 19. Repeat step 18 using detergent.Observe

Data Residual Activity Test: Soapy solution turned bright pink Magnesium and Calcium Salts Test:

Soap CaCl2-all the foam disappeared and a white precipitate MgCa- milky white, white precipitate -Pinkish foam formed after sodium carbonate addition Detergent CaCl2-cloudy white color with no precipitate MgCa- cloudy white color with no precipitate

Oil Test: Tube 1(oil and distilled water)- clear with bubbles Tube 2(oil and soap)- mostly clear with a few white particles and foam Tube 3(oil and detergent)- light pink on the bottom with bubbles Dilute Acid Test: Soap - Reached pH 1 after 2-3 drops Detergent- Reached pH 1 after 10-12 drops Conclusion To start the experiment, 0.7 grams of sodium hydroxide was added to a deionized water and ethanol mixture in a round bottom flask. The flask began to heat after the addition of the sodium hydroxide. Grapeseed oil was chosen for this experiment and 1 mL of the oil was added to the flask. The solution was refluxed for 45 minutes to allow the triglyceride ester bonds to break and carboxylic acid and alcohol to form. Next, 4.0 grams of sodium chloride was dissolved in 10 mL of water. The hot reflux mixture was added to the sodium solution, which is a good solution for the negative oxygen from the carboxylic acid to find positive ions. After the solution cooled , the liquid was clear with yellow clumps throughout. Vacuum filtration was used to collect the soap pieces from the solution. A series of test were performed using the fresh soap. Residual alkalinity was tested first by dissolving a small pellet of soap in 1.5 mL of ethanol then by adding two drops of phenolphthalein.The solution turned bright pink indicating it was basic with a lot of residual alkalinity, which can be harmful to the skin. This is where an error occurred. The phenolphthalein left a residue in the syringe turning everything it came in contact with pink. Next time, the syringe would be cleaned more thoroughly in between to avoid cross contamination. The second test focused on the effects of calcium and magnesium salts on soaps and detergents. In a beaker, 0.35 grams of soap was dissolved in 25 mL of distilled water. Next, 2.5 mL of the solution was placed in 2 test tubes and shaken. After adding 3 drops of CaCl2 to the first tube,all the foam disappeared and a white precipitate formed. In the second tube, 3 drops of MgCl2 were added and the solution became milky white with a white precipitate.Once 0.3 grams of sodium carbonate was added, a white and faint pink foam solution formed.After a minute, the solutions were pink on the top and clear on the bottom. In another 2 test tubes, a detergent solution was added and the test were repeated.The tubes with CaCl2 and MgCl2 had the same

reaction, a cloudy white color with no precipitate. The next test performed was to show effects of oil in different environments. To start, 2 drops of oil were placed into 3 test tubes. In the first tube, distilled water and oil were mixed and the solution was just clear with small bubbles. In the second tube, soap and oil were inside and the solution was mostly clear with a few white particles and foam on the top. In the third tube , oil and detergent were inside and the solution turned light pink on the bottom with bubbles. The last test was used to observe the effect of dilute acid. Sulfuric acid was added to the remaining soap solution until it turned acidic (pH 1) , which it turned after about 2 drops. When the sulfuric acid was added to the detergent, it took about 10-12 drops to make it acidic. They required a different amount of drops because of their effects with hard water. When soap comes in contact with hard water it loses its negative charge, no longer allowing to dissolve and attach itself to dirt. References

Auburn University Department of Chemistry,Organic Chemistry 1I Laboratory Manual,2018;Hayden -McNeil, LLC: Plymouth,MI,2018...