UNIVERSITI TEKNOLOGI MARAFAKULTI KEJURUTERAAN KIMIAENGINEERING CHEMISTRY LABORATORY(CHE485)

NAME : WAN NUR SAHILAH BINTI WAN ABDULLAHSTUDENT NO :2013434256GROUP : 7EXPERIMENT : 6 SOAPS AND DETERGENTDATE PERFORMED : 21 NOVEMBER 2013SEMESTER : 1PROGRAMME / CODE : EH220SUBMIT TO : DR. ABDUL HADI

NOTitleAllocated Marks (%)Marks

1Abstract/Summary5

2Introduction5

3Aims5

4Theory5

5Apparatus5

6Methodology/Procedure10

7Results10

8Calculations10

9Discussion20

10Conclusion10

11Recommendations5

12Reference5

13Appendix5

TOTAL MARKS100

Remarks :Checked by :------------------------------Date :1.O ABSTRACT / SUMMARYAn experiment of preparation of soap and comparison of prepared soap and synthetic detergent are conducted. Precipitation, emulsification and cleaning ability are the properties that become the point of comparison. From the experiment, it can be concluded that the abilities forming precipitates can be seen clearly in soap solution while the synthetic detergent does not form any precipitate at all. Besides, soap has the properties of emulsifying oil whereas detergent does not. Thus, the synthetic detergent is more better than soap in cleaning. The experiment is successfully conducted.

2.O INTRODUCTIONSoaps are mixtures of sodium or potassium salts of fatty acids which can be derived from oils or fats by reacting them with an alkali (such as sodium or potassium hydroxide) at 80100 C in a process known as saponification. The molecules composed of both fat and water soluble. This molecule has a long hydrocarbon tail that allows it to dissolve grease, and a polar head that is water soluble. The head is the sodium or potassium salt of an organic acid. Sodium fatty acids such as lauric (vegetable oil), palmitic (palm oil), and stearic (animal fat) acids are just a few examples of soaps.All organic acids contain the RCO2H functional group, where R is the shorthand notation for methyl, CH3-ethyl CH3CH2-, propyl , CH3CH2CH2-, or more complex hydrocarbon chains called alkyl group. All esters contain the RCO2R functional group. The hydrocarbon chain in soap may contain saturated or non-saturated chains. Tristearin, is an example of a saturated fats . In a saturated fat all of the C-C bonds in the R group are single bonds. Another example of a saturated fat has R with the structure CH3CH2CH2. This fat is found in milk and butter. Animal fats contain mostly saturated fats. Vegetable fats, on the other hand, are mostly unsaturated fats.In an unsaturated fat the R group contains C-C double bonds. For example, in an unsaturated fat found in olive oil, the R group is CH3(CH2)7=CH(CH2)7.

Fats and vegetable oils are triglycerides. They are eaters derived from three fatty acids. A triglyceride is made from three lauric acid molecules. Saponification is usually a process by which triglycerides are reacted with sodium or potassium hydroxide to produce glycerol and a fatty acid salt, called 'soap'. Lipids that contain fatty acid ester linkages can undergo hydrolysis. This reaction is catalyzed by a strong acid or base. Saponification is the alkaline hydrolysis of the fatty acid esters. Example for the process is :

A lone pair of electrons on the O is attracted to the partially positively charged C atom in the C=O bond in the ester. The C-OR bond breaks thus generate a carboxylic acid and an alcohol. They are converted to their sodium salts in the presence of NaOH carboxylic acid. Three fatty acids are produced when a triglyceride is saponified. The R groups in the triglyceride may or may not have the same chain length. Thus, from the saponification of a particular triglycerides, different types of soaps may be produced.

3.0 OBJECTIVESThe aims of conducting this experiment are to prepare soap and compare the properties of soap to that of a synthetic detergent.

4.0 THEORYMost organic acids are weak acids. Soap is the salt of weak acid. When soap dissolves in water, hydrolysis occurs to some extent. Due to partial hydrolysis of the acid, soap solutions tend to be slightly alkaline (basic).The cleansing action of soaps results from two effects. First,soaps are wetting agents that reduce the surface tension of water, that allowing the water molecules to encounter the dirty object. They are also emulsifying objects. Dirt frequently consists of a grease or oil along with other organis species. In general, organic compunds are non-polar. While water is a polar species. These two substances will not dissolve in each other because of their dissimilar characteristics. Soaps cross the boundary between polar and non-polar because they contain a polar hydrophobic (water hating) end and a polar hydrophilic end.Soaps have both polar and non-polar molecular regions, hence they are soluble in both polar and nonpolar species. The hydrophobic (non polar) portion of soap is soluble in non polar compunds like grease and oils. While the hydrophilic (polar) end dissolves in water. Soap molecules surround grease and oils and break them up into microscopic droplets, which can remain suspended in water. These suspended microscopic droplets are called micelles. Micelles contain very small amounts of oil or grease in their center. Thus, oil or grease dissolved in water forms an emulsion; a form of suspension in water.

Water supplies in certain areas are acidic as a result of acid rain or pollution, or hard due to dissolved mineral content. Both acidic and hard water reduce the cleansing action of soap. Soap is the salt of a weak acid and in the presence of a stronger acid, the sodium salt is converted to an insoluble organic acid. Normally, soaps made from sodium and potassium fatty acids are soluble in water. However, in the presence of these metal ions, the and convert to insoluble salts. In eitherv acidic or hard water, the soluble soaps form insoluble salts which leave scummy rings on bathtubs and black areas on shirt collars. The cleansing ability of soap is reduces becaues soap molecules are removed from the solution. There are several techniques used to circumvent the problems generated by hard water. Water can be softened via removing hard water ions from solution using ion exchange techniques or by adding water-softening agents, such as sodium phosphate or sodium carbonate. Water softening agents react wiht the removing them from the water and thus preventing the reaction of these ions with soap.3(aq) + 2(aq) Ca3 (PO4)2 (s)(aq) + C(aq) MgCO3 (s)Therefore, Syndets were developed to overcome the soap hard water problem. Syndets differ from soaps in that the nonpolar fatty acids groups are replaced with alkyl or aryl sulfonic acids RROSO3H). The alkyl or aryl sulfonics acids have long hydrophobicncarbon chains and a hydrophilic sulfonate end. The difference in polar groups is one of the key distinctioun between a soap and a synthetic detergent. Syndets form micelles and cleanse in the same manner as soaps. Two examples of synthetic detergents are sodium lauryl sulfonate and sodium 4-laurylphenylsulfonate. Sulfonic acids are stronger than carboxylic acids, hence Syndets do not preciitate in acdic solutions. Futhermore, alkyl and aryl sulfonates do not form insoluble salts in the presence of typical hard water ions. Thus, synthetic detergents remain soluble in both acidic and hard water.

MATERIALS Ice bath 1M Hydrochloric acid 1% FeCl2 solution 1% MgCl2 solution 1% CaCl2 solution Distilled water Mineral oil Synthetic detergent Sodium chloride Sodium hydroxide Vegetable oil Ethanol

APPARATUS

Erlenmeyer flask Weighing electronic Petri dish Litmus paper pH metre electrode measuring cylinder cloth strip test tube with racks beaker vacuum filtration apparatus stirring bar magnetic stirrer

5.0 PROCEDURE5.0.1 Soap Preparation1. 250ml of vegetable oil is placed in a 250-ml Erlenmeyer flask. 20ml of ethanol and 25ml of 6 M sodium hydroxide solution are added to the flask. The mixture is stirred using a stirring bar to mix the contents of the flask. Note : carefully smell the alcohol by wafting it towards your nose.2. The 250-ml flask is heated in a 600ml boiling-water bath.3. The mixture is stirred continuously during the heating process to prevent the mixture from foaming. The flask is removed from the boiling-water bath until the foaming subsides,if the mixture should foam to the point of nearly overflowing. Then, it is heated continuously for 20-30 minute or until the alcohol odor is no longer detectable.4. The paste-like mixture is removed from the water bath and the flask is cooled in an ice bath for 10-15 minutes.5. The vacuum filtration apparatus is assembled while the flask is cooling. The vacuum flask is secured to a ring stand with a utility clamp in order to prevent the apparatus from toppling over.6. A piece of filter paper is weighed to the nearest 0.001g and the mass is recorded. The filter paper is placed inside the Buchner funnel. The paper is then moisted with paper so that fits flush in the bottom of the funnel.7. Once the flask has cooled, 150ml of saturated sodium chloride (NaCl) solution is addewd to the flask to salt out the soap.8. The water at the aspirator is slowly turned on. The mixture is poured from the flask into the Buchner funnel. Once all the liquid has filtered through the funnel, the soap is washed with 10ml of ice-cold water. The suction filtration is continued until all the water is removed from the soap.9. The soap is removed from the funnel and it is pressed between two paper towels to dry it. The filter paper is weighed and dried soap, the mass is recorded to the nearest 0.001g and the mass of the mass by difference is determined and also recorded.

5.0.2 Comparison of soap and detergent properties ; precipitation and emulsification.1. A stock solution is prepared by dissolving 2 g of the prepared soap in 100ml of boiling,distilled water. The mixture is stirred until the soap has dissolved and the solution is allowed to cool. 2. Step 1 is repeated using 2 g of synthetic detergent. When both solutions are cool, the ph of each solution is determined using ph paper.3. Three test tubes are labeled as test tube 1,2 and 3. Four drops of mineral oil are added to each test tube. 5ml of distilled water is added to test tube 1 , 5ml of stock soap solution is added to test tube 2, 5ml of stock synthetic detergent to test tube 3.4. Each solution is mixed by shaking and is let to stand for three to five minutes. Note for which of the solutions, if any, emulsifies the oil by forming a single layer.5. The mixtures are poured into the Waste Container. The three test tubes are cleaned and dried.6. Three more test tubes are labeled as test tubes 1,2, and 3. 2ml of stock soap solution is placed in each of the three test tubes. 2ml of 1% CaCl2 solution solution is added to test tube 1. 2ml of 1% MgCl2 solution is added to test tube 2 and 2ml of FeCl2 is added to test tube 3. Each test tube is shaked to mix the solutions. The observations are recorded.7. Four drops of mineral oil is added to each of the test tubes in step 6. Each test tube is shaked to mix the solutions and is let to stand for three to five minutes. Note ; which of the solutions, if any, emulsifies the oil by forming a single layer.8. Steps 6-7 are repeated by using 2ml of stock detergent solution. And is indicated which solutions form a precipitate.9. Note which of the solutions, if any, emulsifies the oils by forming a single layer.10. The mixtures are poured into the Waste Container. The test tube is then cleanes and dried.11. 5ml of stock soap solution is placed in the cine clean test tube and 5ml of stock detergent solution in a second test tube. 1 M HCl is added one drop at a time to both solutions until the ph in each test tube is equal to 3. The number of drops of acid added is calculated to each mixture. Does a precipitate form in either mixture is observed.12. One drop of mineral oil is added to each test tube in step 11. Each test tube is shaked to mix the solution. Is the oil emulsified in either mixture is indicated.

5.0.3 Comparison of the cleaning abilities of a soap and detergent.1. Three beakers are cleaned, dried and labeled. 20ml of stock soap solution(from step 1 in 5.0.2) is placed in the first beaker. 20ml of stock detergent solution (from step 2 in 5.0.2) is placed in the second beaker. 20ml of a commercial liquid is placed in third beaker.2. Three cloth test trips are obtained that have been soaked in tomato sauce and one strip is placed in each of the beakers. On cloth strip is placed in beaker 1. One cloth strip in beaker 2 and one cloth strip in beaker 3. Each solution is stirred repeteadly with a stirrer bar for 5 minutes.3. The cloth strips are removed from the soap and detergent solution and the excess water is squeezed out. Compare each cloth strip visually to determine their relative cleanliness. The observations are recorded.

6.0 RESULTS6.0.1.Soap preparationMass of filter paper (g)0.570

Mass of filter paper (g) + mass of soap (g)84.706

Mass of soap recovered (g)84.136

Mass of empty dish (g) = 45.198Mass of detergent (g) = 2.0224Ph of stock solution = 10

6.0.2.Comparison of soap and detergent propertiesBrand name of synthetic detergent

pH of soap solutionpH 10

pH of synthetic detergent solutionpH 8

Test tubeEmulsification occured

4 drops of oil + 5ml of distilled waterNo emulsification occured. Oil droplets formed

4 drops of oil + 5ml of soup solutionEmulsification occurs.Oil dissolves in solution

4 drops of oil + 5ml of detergent solutionNo emulsification. Very tiny oil droplets and bubbles formed

SystemPrecipitateOil emulsified

SoapSyndetSoapSyndet

CaCl2Yes (white)NoLight blue solutionYesNo

MgCl2Yes (white)NoYesNo

FeCl3Yes (white)NoYellow orangeYesNo

AcidicYes (white)NoLight blue solutionYesNo

SoapDetergent

No of drops of HCl43

Cleaning abilities (decreasing abilities as cleaning agents) :Detergent > soap > commercial fliud

7.0 DISCUSSIONSIn saponification, with the presence of the base, the fatty acid carboxylate ions are formed. These carboxylate ions are able to accept proton since they are the conjugate bases of the fatty acids. Therefore, when placed in water, these conjugate bases are able to accept protons from any source including water.Hard water is said contains of calcium ions and magnesium ions. These ions are leached from ground water that flowing over rock formations containing limestone and other minerals. Hard water interferes with the cleaning action of soaps. Sticky scum which are insoluble compounds are formed when soap is added to hard water. This scum leaves a deposit on clothes, skin, and hair also. However, hard water leaves a deposit of calcium carbonate when boiled. This build up in tea kettles and inside hot water heaters.From the observations obtained from this experiment, the soap form precipitates in all of the solutions added as well emulsifies the oil. This may not appear as good characteristics for soap as a cleaning agent if it forms precipitate and emulsifies oil on cloth. Neverthless, detergent is better cleaning agent as it forms no precipitate and does not emulsifies the oil. Thus, grease and dirt can be claned without invloving any precipitation or oil emulsification. 8.0 CONCLUSIONThe soap is successfully preparedmand the comparison of properties of soap to that of a synthetic detergent, which are precipitation and emulsification are observed. From the experiment, it can be concluded that soap has the abilities of forming precipitates which can be seen clearly whereas detergent forms no precipitate at all. While soap also has the properties of emulsifying oil whereas detergent has not. Thus, detergent is better cleaning agent as it forms no precipitate and does not emulsifies the oil.

9.0 RECOMMENDATIONSThere are a few recommendations that will significantly produce better observations which will not deviate much from the theoretical observations. In order to get more accurate values, a few recommendations and precautions must be considered when performing the experiment. First of all, in this experiment, we should done at least three or two trials then taking the average. By doing so, more accurate and ideal values can be obtained. Secondly, carefully smell the alcohol by wafting it towards our nose. We also have to avoid contact with any chemical reagents involved.Next, any pH reading must be conducted at the same temperature for pH is varying at different temperatures.

9.0 REFERENCES1. Senese,F.(2010, February 02). What Is Soap Made Of. Retrieved Nov 23,2013 from https://antoine.frostbug.edu.2. Charles,E.(2003). Micelles. Retrieved Nov 23, 2013 from https://www.elmhurst.edu.3. Soap As An Emulsifying Agent And Cleaning Action Of Soap.(2012). [Web log spot]. Retrieved Nov 23, 2013 from https://chemistlabs.blogspot.com.4. Anne,M.(n.d.). Soap And Saponification. Retrieved Nov 24, 2013 from https://chemistry.about.com.5. Richard,H.(2006). What Is Saponification. Retrieved Nov 24, 2013 from https://www.realhandmadesoap.com.