ACYL COMPOUNDS: SOAPS AND DETERGENTS
Experiment # 8
To observe the general properties of carboxylic acids.
To compare the acidity of carboxylic acids and phenols. To verify experimentally the interconversion among acyl compounds. To become familiar with the physical and chemical properties of fats and oils and to understand the chemical basis of these properties. To learn how to prepare soap.
To compare the properties of soap and synthetic detergents.
II. Data and Observation
A. Comparison of soaps and detergents
Reaction with blue litmus paper
The hydrolysis was tested with acetic acid, benzoic acid, and sodium benzoate. 2mL water was placed in a test tube and 6 drops of sample was added to each. The mixture was mixed by shaking, examined, and tested with blue litmus paper. The blue litmus paper turned red on every attempt.
2. Reaction with acid
Reaction with 10% NaOH
Reaction with NaHCO3
This test was performed using benzoic acid and phenol. 2mL of water was placed on a test tube. 6 drops of the sample was added, then 10 drops of 10% NaOH. The mixture was examined. The process was repeated using 10% NaHCO3 instead of NaOH. Results were noted on the table above.
B. Hydrolysis of Acyl compound
Test with Blue litmus Paper
Small bubbles, immiscible
Heat evolved, cloudy
*no change heated
The hydrolysis of Acyl compound was performed with acetyl chloride, acetic anhydride, ethyl benzoate, and benzamide as samples. 6 drops or a spatula tip of sample was placed in a test tube. 3mL water was carefully added. The mixture was observed for any sign of reaction. For Ethyl acetate, small bubbles were observed, for Acetyl chloride heat evolved, for the rest, no signs change was evident. Those with no changed seen, Acetic anhydride and Benzamide, were heated for 2 minutes without boiling in a hot water bath. The mixture was cooled. All 4 test tubes of sample mixtures were tested with blue litmus paper.
C. Saponification of coconut oil
For the saponification of coconut oil, 10 mL ethanol was placed in a 400 mL beaker. 15 mL 6M NaOH was added, then 15 mL of coconut oil. The mixture was mixed by swirling. Boiling chips were added and the beaker was covered with a watch glass. The mixture was heated while swirling over a small flame for 15 minutes until the mixture is viscous. Mixture was cooled. 50 mL saturated NaCl solution was added while stirring. The product was filtered. The soap was washed twice with 15 mL ice-cold distilled water. This was allowed to dry until the following meeting.
D. Comparison of soaps and detergents
For the comparison of soaps and detergents, 1 spatula tip of the soap product from saponification of coconut oil was dissolved in 30 mL of warm distilled water. The same was done with a sample of detergent. The mixtures formed were used for the following tests.
Test with red litmus paper
Test with blue litmus paper
Blue (slower reactivity)
The mixtures were both tested on red and blue litmus paper. Although red litmus paper turned blue on both mixtures, it was observed that the red litmus paper turned to blue slowly with the soap mixture while rapidly or upon contact with the detergent mixture.
2. Reaction with acid
Cloudiness settled on the bottom and bubbles formed on top. Layer between is clear...
References: McMurry J. (2010). Foundations of organic chemistry. Philippine edition. Cengage learning asia Pte. Ltd.
Doyle P., Mungal S. (1980). Experimental organic chemistry. New York: John Wiley and Sons, Inc.
Acyl groups (n.d). Retrieved from http://jchemed.chem.wisc.edu/JCESoft/CCA/CCA5/MAIN/1ORG ANIC/ORG12/TRAM12/B/0380011/MOVIE.HTM
Please join StudyMode to read the full document