Preparation and Properties of soap
Experiment 3: Preparation and Properties of Soap
Objectives:
i) To be able to prepare a soap starting with olive oil and animal lard. ii) To examine the chemical properties of the soap that is made. iii) To determine the theoretical yield and experimental yield of soap.
Introduction: A soap is a salt of a fatty acid. Fatty acids are carboxylic acids with a long unbranced hydrocarbon (aliphatic) chains. It contains at least 12 carbons and a carboxylic acid group.
Materials and Apparatus: Olive oil, 95% ethanol, beaker, 50% sodium hydroxide solution, Buchner filter, hot plate, salt solution, magnetic stirrer, filter funnel, glass rod, filter paper, weighing balance, watch glass and measuring cylinder.
From the diagram above, we can clearly see that the ionic (highly polar and charges) natures of salts makes them soluble in water. However, the non-ppolar hydrocarbon (aliphatic) tail of the soap molecules would cause them to be miscible with non-polar substances and enable them to dissolve in water. Normally, solid soaps are consist of sodium salts of fatty acids and liquid soaps consist of potassium salts of fatty acids. Soap can be prepared by a process known as saponification. Historically, soaps were made by boiling the fat of animal, lye and in a aqueous NaOH and KOH solution containing potash. Of course, this was done long time ago before anyone had any idea of understanding the chemical transformations. Now, we know that this process is a reaction of esters with a strong base such as KOH or NaOH. The esters, triglycerides are the main constituents of vegetable oil and animal fats. The triglyceride is a tri-ester come along with 3 long fatty acid hydrocarbon chain. When triglyceride reacts with 3 equivalents strong aqueous base solution such as NaOH or KOH, the three ester bonds are hydrolyzed to yield 3 fatty acid salts (soap molecules) and one glycerol. The saponification can also be called “base hydrolysis”.
Industrially, soap is
Objectives:
i) To be able to prepare a soap starting with olive oil and animal lard. ii) To examine the chemical properties of the soap that is made. iii) To determine the theoretical yield and experimental yield of soap.
Introduction: A soap is a salt of a fatty acid. Fatty acids are carboxylic acids with a long unbranced hydrocarbon (aliphatic) chains. It contains at least 12 carbons and a carboxylic acid group.
Materials and Apparatus: Olive oil, 95% ethanol, beaker, 50% sodium hydroxide solution, Buchner filter, hot plate, salt solution, magnetic stirrer, filter funnel, glass rod, filter paper, weighing balance, watch glass and measuring cylinder.
From the diagram above, we can clearly see that the ionic (highly polar and charges) natures of salts makes them soluble in water. However, the non-ppolar hydrocarbon (aliphatic) tail of the soap molecules would cause them to be miscible with non-polar substances and enable them to dissolve in water. Normally, solid soaps are consist of sodium salts of fatty acids and liquid soaps consist of potassium salts of fatty acids. Soap can be prepared by a process known as saponification. Historically, soaps were made by boiling the fat of animal, lye and in a aqueous NaOH and KOH solution containing potash. Of course, this was done long time ago before anyone had any idea of understanding the chemical transformations. Now, we know that this process is a reaction of esters with a strong base such as KOH or NaOH. The esters, triglycerides are the main constituents of vegetable oil and animal fats. The triglyceride is a tri-ester come along with 3 long fatty acid hydrocarbon chain. When triglyceride reacts with 3 equivalents strong aqueous base solution such as NaOH or KOH, the three ester bonds are hydrolyzed to yield 3 fatty acid salts (soap molecules) and one glycerol. The saponification can also be called “base hydrolysis”.
Industrially, soap is