SYNTHESES OF SOAP AND DETERGENT Francis Dimaandal, Inri Dumlao, Mark Kevin Eusebio Dennis Giron and Pia Hipolito Group 4 2A Biochemistry Organic Chemistry Laboratory ABSTRACT Synthesis of soap and detergent is the actual creation of soap and detergents itself. Soap is any sodium or any potassium salt of fatty acids that is either derived from animal or vegetable fat. Various methods such as saponification, where as fats are broken to form impure salts of fatty acids and glycerol. This is simply known as crude soap, ready for further purification to produce a commercially available soap in our homes and offices. In this experiment, to form soap, has consumed the following solutions and solvents such as 30 mL 6M NaOH, 15 mL coconut oil, 50 mL cold saturated NaCl solution. It is performed to synthesize soap and detergents starting from oil and sodium hydroxide to form fatty acids and glycerol as well as to compare the behavior of the soap and the detergent in hard water.
INTRODUCTION
Soap is any salt of a fatty acid from the addition of alkali solution. As tested, soap has a capability to bind to grease or any oils as stains in garments. It serves as a surfactant in conjunction to water. This function of soap is attributed to micelles which have coats of polar carboxylate groups on the outside, encasing a hydrophobic pocket that can surround any grease particles.[1] As of today, the most common way of creating soap is through the cold process method. “Lye” soap is the common product of this modern homemade soap production. The rational behind the oil or grease is removed when the garment stained with oil is dictated by the “like dissolves like” principle. Micelles’ explains this function in a diagram.
as soap is to water. The micelle’s “tail” may extend or become highly branched for as long as it still dissolves in non polar substances like oil.[2]
EXPERIMENTAL
A. Compounds, solvents, and solutions utilized and consumed. 20% of NaOH, 6M NaOH, concentrated H2SO4, 1% CaCl2, 1% MgCl2, solid NaCl, saturated NaCl, phenolphthalein, dodecanol (C12H25OH), vegetable oil (coconut oil). B. Procedure DIAGRAM2. Reaction sequence for soap
DIAGRAM1. Micelles structure
As we all know water is polar and by adding oil, a non polar substance, it will not mix. By adding soap, which in fact has bi-polar reactivity between water and oil, oil and water will mix through the suspension of oil in soap
1. Preparation of Soap Prepare a mixture of 30 mL of 6M NaOH and 50 mL of distilled water. Transfer these into a 500 mL beaker, heat using a small flame, and stir frequently. Add a total amount of 15 mL coconut oil in the mix gradually and heat for about 15 to 20 min. with
stirring, just to ensure that water is replaced via evaporation. To test if the saponification is complete, add a drop of the mix into a milliliter of water. If the mix still exhibits a presence of coconut oil, heat again for 15 to 20 min. along with stirring. Test again; expect that the mix is complete of saponification. Stir until mix is homogenous. Pour it into a 50 mL of cold, saturated solution of NaCl while still hot. As the soap forms, filter the precipitated soap through a cheese cloth. The filtrate, a liquid, is now ready for glycerol test. Wash the collected soap in 5 mL ice cold water twice. Squeeze again to remove excess water. Dissolve in an evaporating dish, add 10 to 20 mL of water to dissolve soap, and evaporate into a jelly like consistency. Cool and pour into a mold, and use this formed soap in hard water behavioral test. 2. Extraction for Glycerol Neutralize the filtrate, the liquid collected from a repeated squeezing of the soap, with diluted HCl. If it’s not clear, filter it. Evaporate it into small volume or a syrupy consistency and allow cooling down. Extract the syrup and add 95% ethanol then filter again. Evaporate the alcoholic extract in a water bath and now the residue that remained has glycerol. 3. Glycerol test To the residue, add a potassium bisulfate (KHSO4). mixture strongly, meaning, temperatures. Take note of formed.
pinch of Heat the at high the odor
4. Preparation of Detergent In preparing the detergent, place 5 mL of dodecanol (C12H25OH) into a 100 mL beaker. Add gradually a total amount of concentrated H2SO4 while stirring for about a min. after the acid is completely added and let stand for an additional 10 min. Mix well 5 mL 6M NaOH with 10 mL of water and add 4 drops of phenolphthalein which may
begin to fade in the presence of a strongly basic solution. After 10 minutes has passed, add it now to the dodecanol- sulfuric acid mix and stir until the tinge of phenolphthalein disappears. There should be a large amount of detergent formed. Fill a 250 mL of one third of ice and 10 g of NaCl and thoroughly mix. Add water until it reaches a total amount of 75 mL. Pour the detergent mix to make it lump on the cold NaCl ice mix. Then filter it in a three layered cheese cloth. Wash the collected detergent in two portions of water with 10 mL each portion. Then finally squeeze to take of any excess water and prepare for hard water behavioral tests. 5. Hard Water Behavior DIAGRAM3. 2C17H35COONa + (C17H35COO)2Ca + 2Na+
Ca2+ →
Above is an example of a reaction mechanism of sodium stearate soap to hard water. Place 5 mL of both soap solution and the detergent solution into two test tubes each sample. Add 2 mL 1% sdCaCl2 to detergent solution and soap solution. Do the same to the rest of the test tubes with 2 mL 1% MgCl2. mix but not shake the mixtures and note any precipitates formed if it does so. Add now 4 drops of cooking oil to each tube put a stopper and vigorously shake the four tubes. Observe and record any emulsifying ability of the soap and detergent in each tube. Indicate whether if formed suds as heavy, light, few, or none at all.
RESULTS AND DISCUSSION TABLE1. Hard Water test w/ some physical states soap detergent color and white white appearance solidified solids gelatin solubility insoluble soluble in 1% CaCl2 solubility insoluble soluble in 1% MgCl2 emulsifying light suds more suds ability present As seen from above, these are the behaviors exhibited as the hard water test is performed. According to these observations, soap slightly produces suds in hard water while detergent can yield more. As a personal experience, in Saudi Arabia, a tanker of water delivers cheap hard water. As a result, soap scum builds up on our containers and tiles. Taking a bath is also difficult. Shampooing is easy since it can be classified as a detergent as well. But, as for soap, it does not have any effect even on our hands. A bypass to this occurrence is adding baking soda into the water, dissolving the soap scum that could possibly develop. To the emulsifying ability test in the laboratory, light suds on soap indicate that calcium or magnesium ions are still present in the water. This is due to the high reactivity of soap to ions. Unlike in detergents, ions do not bother the reaction, which is the main reason why detergents works best in hard or soft water unlike soaps, which only react with soft waters. Observations test:
from
the
Glycerol
As the potassium bisulfate is added to the glycerol and heated, it exhibited a sweet butter-like odor. This indicates that a fatty acid derivative is present in the mixture.
Fatty acid or any of its derivatives when burned, exhibits a burnt fat odor but in this case, glycerol has a sweet taste and buttery odor when subjected to heating.
REFERENCES [1] en.wikipedia.org August 29, 2010 [2]chemlab.trueman.edu/ CHEMLAB100/SAPONIFICATION.pdf August 29, 2010 [3] Bayquen, A.V., Cruz, C.T., de Guia, R. M., Lampa, F.F., Pena, G.T., Sarile, A.S., Torres, P.C. (2009). Laboratory Manual in Organic Chemistry. C&E publishing, Inc.
