- 7 125 Ml Beaker Or Flask Evaporating Dish Enough To Cover The Beaker Materials 10 Ml Vegetable Oil 15 Ml 95 Ethanol 1 (149.84 KiB) Viewed 50 times
- 7 125 Ml Beaker Or Flask Evaporating Dish Enough To Cover The Beaker Materials 10 Ml Vegetable Oil 15 Ml 95 Ethanol 2 (149.1 KiB) Viewed 50 times
- 7 125 Ml Beaker Or Flask Evaporating Dish Enough To Cover The Beaker Materials 10 Ml Vegetable Oil 15 Ml 95 Ethanol 3 (97.57 KiB) Viewed 50 times
7 125 ml beaker or flask evaporating dish enough to cover the beaker Materials: 10 ml Vegetable oil. 15 ml. 95 % ethanol 25 mL 6 M NaOH- 50 mL saturated NaCl ice-water stirring bar magnetic stirrer-heater wire gauze spatula Cheese cloth Paper cloths funnel 50 ml beaker Ice-water bath Beaker tongs 10 vials and rack Mineral Oil pH paper Drops of 5% CaCl₂ Drops of 5% FeCl3 Drops of 5% MgCl₂ Saturated NaCl (360 g/L water at 25°C) Detergent solution (0.3 g detergent in 30 mL water) Procedure A. Preparation of Soap: 1. In a 250 mL flask, add the following with caution: a) Place 10 mL of vegetable oil and 15 mL 95% ethanol to dissolve the oil. b) SLOWLY and carefully add 25 mL of 6 M NaOH. c) Add a small magnetic stir bar. 2. Stir the mixture on a magnetic stirrer-hotplate. 3. Gently heat the mixture using a low setting on the hot plate (3 to 4) with constant stirring for about 20-30 minutes. Cover the flask with a small watch glass to prevent any spattering of the mixture, and minimize evaporation of alcohol. Do not let the mixture overheat or foam over or boil to dryness. Wear goggles at all times. After the mixture being heated for about 20-30 minutes, the odor of alcohol will disappear indicating the completion of the reaction. A transparent (viscous) homogenous mixture. containing of soap, glycerol and excess NaOH is obtained. 5. Test the mixture if saponification is complete by placing a few drops of the solution in a test tube of deionized water. If you see fat droplets floating on top of the water, saponification is not complete. And allow the mixture to boil for another 10 minutes. 6. Turn off the heater and add 25 mL deionized water to the beaker. Place the beaker on the bench top and allow the mixture to cool to room temperature for about 5 minutes. 7. Place the soap reaction flask into a 500-ml beaker (with ice water) and cool for about 10 minutes. 8. To separate or "salt-out" the soap, add 50 mL of saturated NaCl solution to the soap mixture. Stir thoroughly. Allow it to cool completely (in ice bath preferably). Please note that the solid cake that forms is the SOAP. The liquid that is floating on the top of water is glycerol. Decant the liquid portion from the solid cake. Wash the solid cake with 10 mb ice cold water. Decant or filter the precipitated soap on a gravity funnel using cheese cloth. 9. باس بار
as much Weigh the dried soap. B. Properties of a soap Emulsifying Properties. 1. Shake 5 drops of mineral oil in a test tube containing 5 mL of water. A temporary emulsion tiny oil droplets in water will be formed. 2. Repeat the same test, but this time add a small piece of the soap you have prepared befc shaking. Allow both solutions to stand for a short time. 3. Compare the appearance and the relative stabilities of the two emulsions. 4. Record your observations on the Report Sheet. Hard Water Reactions. 1. Place about one-third spatula full of the soap you have prepared in a 50-mL beaker containin 25 mL of water. 2. Warm the beaker with its contents to dissolve the soap. 3. Pour 5 mL of the soap solution into each of 5 test tubes (nos. 1, 2, 3, 4, and 5). 4. Test no. 1 with 2 drops of a 5% solution of calcium chloride (5% CaCl₂), no. 2 with 2 drops o a 5% solution of magnesium chloride (5% MgCl₂), no. 3 with 2 drops of a 5% solution or iron(III) chloride (5% FeCl3), and no. 4 with tap water. The no. 5 tube will be used for a basicity test, which will be performed later. 5. Shake each test tube. Record your observations on the Report Sheet. 6. Repeat procedures 3-5, but replace the soap solution with detergent solution. Alkalinity (Basicity). 1. Test soap solution no. 5 with a wide-range pH paper. 2. What is the approximate pH of your soap solution? Record your answer on the report sheet. 3. Repeat procedures 1-2 with detergent solution no. 5. Record your observation.
2. Emulsifying Action: Observation: Oil+ water Observation: Oil + soap solution Explain the difference in results: 3. Properties of Soap and Detergents Substance pH of Effect of adding salts solution CaCl₂ FeCl gCl2 Soap 14 drang pink. light pink Detergent new life w The meal ions Cat2, Fe, Mg2 all contribute to the formation of hard water. What differences did you observe when the metal ions Ca+2, Fet and Mg¹2 were added to a soap or detergent. Do +2 you think that a soan ld make a better cleansing onont in hard water? Explain. How does the pH of the soap solution that you prepared compare with those of the commercial detergent? Which of these products would have the harshest effect on skin? Explain. 4. What are the two main disadvantages of soaps versus detergent? اس راش Tap water