In this experiment a triglyceride will certainly be hydrolyzed in order to prepare glycerol plus the salt of the equivalent fatty acids (soap).

You are watching: Draw the products of the saponification of the following triacylglycerol (triglyceride):


Soap is produced by the saponification (hydrolysis) of a triglyceride (fat or oil). (See Figure 1.) In this process the triglyceride is reacted via a strong base such as sodium or potassium hydroxide to create glycerol and fatty acid salts. The salt of the fatty acid is called a soap. Fatty acids are straight-chain monocarboxylic acids. The the majority of prevalent fatty acids variety in dimension from 10-20 carbons and many regularly have actually an also number of carbon atoms including the carboxyl team carbon. The carbon-carbon bonds in saturated fatty acids are all single bonds, while unsaturated fatty acids have one or more carbon-carbon double bonds in their chains. One example of a saturated fatty acid is palmitic acid, CH3—(CH2)14—CO2H. Fatty acids are hardly ever discovered as cost-free molecules in nature yet are a lot of regularly a component of a larger molecule called a triglyceride. Triglycerides consist of a three-membered carbon chain (glycerol backbone) via a fatty acid bonded to each of the 3 carbon atoms in the glycerol backbone. The bond between the fatty acid and also the glycerol backbone is described as an ester linkage. In the saponification process, the ester linkage is broken to develop glycerol and soap.

The saponification process is a hydrolysis reactivity, which is the reversal of the esterification reaction. In this experiment, we will certainly usage a saturated fat made from hydrogenated olive oil (glycerol tristearate) to prepare a soap, which will certainly be primarily sodium steaprice.


Complete the pre-lab assignment in WebAsauthorize.


Place 0.18 g of glycerol tristearate in a 5 mL conical vial. Add 1.5 mL of a 50:50 water:ethanol solution that includes 0.18 g. of sodium hydroxide. Add an air condenser and gently reflux the mixture by heating it on a warm plate equipped through an aluminum heating block for 30 minutes. Monitor the temperature very closely to stop the evaporation of the ethanol. At the end of the reaction duration, some of the soap will certainly have precipitated. Transfer the mixture to a tiny Erlenmeyer flask containing a solution of 0.8 g of sodium chloride in 3 mL of water. Collect the precipitated soap on a Hirsch funnel and also wash it cost-free of excess sodium hydroxide and also salt using 4 mL of ice water. Test the soap by including a very little piece to a test tube with 4 mL of water. Cap the tube and also shake it. Note the size and stability of the bubbles. Add a crystal of magnesium chloride to the tube and also shake aobtain. Note any differences. Repeat the same tests with a couple of grains of commercial laundry detergent and record your results in the lab worksheet.

In-Lab Questions

Downpack and also print the following worksheet. You will usage this worksheet to record your answers to the In-Lab questions.

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Record the complying with data.
Inquiry 3: Theoretical Yield of sodium stearate__________________ mol,__________________ gInquiry 4: Percentage Yield__________________
Concern 6: Observations:Soap in plain water ________________________________________Soap in simple water plus magnesium chloride _________________________________Detergent in simple water___________________________________Detergent in plain water plus magnesium chloride_____________________________