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carboxylate salt of a fatty acid is formed, which is soap. Any natural fat source, such as vegetable oil, contains a mixture of different fatty acids. So, many different carboxylate salts are formed in the soap. Carboxylate salts are part hydrophilic and part hydrophobic. The ionic portion is hydrophilic and the long chain is hydrophobic. An emulsifier allows materials, such as dirt or grease that aren’t usually soluble in water, to dissolve in water. Hard water has a high level of Group II metal cations, like Ca+2 and Mg+2. The carboxylate salts of fatty acids lose their effectiveness as emulsifiers when they are in hard water. In acidic water, the carboxylate salts are converted to fatty acids. Fatty acids are insoluble. Experimental:First, 12mL of oil was added to a 125mL Erlenmeyer flask. Then 40mL of 95% ethanol and 10mL of 25%NaOH were added to the Erlenmeyer flask. After that the flask was placed in a hot water bath. The mixture was stirred constantly was it was being heated. This was heated for 45 minutes. The disappearance of the ethanol odor was the indicator that the reaction was done. Then, the mixture was cooled in an ice-water bath. 50mL of saturated sodium chloride was added to precipitate the soap and it was stirred. Then the soap was filtered by using suction filtration through a Buchner funnel. The soap was then washed with two 10mL portions of ice cold water. After that, the soap was driedby letting air suck through it for 5 to 10 minutes. Once it was dried enough the suction
was turned off. Observations of the soap were recorded. Then observations of the soap were then compared to another group’s soap. Once the soap was made, the properties of the soap were tested by preparing two test tubes both with 5mL of distilled water and 15 drops of mineral oil. A small amount