LAS4 CHE005L Organic Chemistry Lab Activity Sheet 4 PDF

**CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_...

**CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **ACTIVITY NO.4** **LABORATORY TECHNIQUES AND OPERATIONS PART 3:** **DISTILLATION AND HEATING UNDER REFLUX** **Learning Objectives** **At the end of the activity, you will be able to:** Demonstrate the distillation process for separating a mixture and purifying a liquid. Show the heating under reflux technique. **Materials** Pen, table salt (sodium chloride), distilled water, distilling flask, two (2) universal/extension clamps, two (2) clamp holders, (2) iron stands/ring stands, condenser, wire gauze, thermometer, cork or cotton, cork borer distillation adapter, 50- or 100-mL Erlenmeyer flask, two (2) rubber tubing, two (2) 10-mL graduated cylinders, eight (8) test tubes, test tube rack, test tube holder, dropper, AgNO~3~ solution, wire loop, concentrated HCl solution, methyl salicylate (oil of wintergreen), 10% NaOH solution, Florence/boiling flask, 100-mL graduated cylinder, water bath, litmus paper, concentrated H~2~SO4 solution, stirring rod, funnel, tripod, filter paper, 250-mL beaker, bromine water, FeCl~3~ T.S., watch glass, methanol, hot plate, top-loading balance or analytical balance **Introduction** Distillation is one of the most common methods of purifying a liquid. It is a very simple method in which a liquid is brough to a boil, the liquid becomes a gas, the gas condenses and returns to the liquid state, and the liquid is collected. Reflux refers to an experimental method that involves heating a reaction mixture to the boiling point temperature of the reaction solvent and inducing the solvent to recondense back into the reaction flask using a condenser. Reflux under heating is a simple and efficient way to maintain a constant reaction temperature. For these activities or objectives to be realized, methods involving usage of condenser and other glassware should be practiced in experimental laboratory. The techniques to be demonstrated are distillation and reflux under heating. All of these techniques involve changes in the physical state of a chemical compound, whether it is as a solid, liquid, gas, or present in a solution. This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **A. [Distillation]** **Procedure:** 1\. Prepare a salt-water mixture. Mix 30 g of sodium chloride and 50 mL of distilled water in a distilling flask. 2\. Assemble the distillation set-up. a\. First, the universal/extension clamp and clamp holder are fixed to an iron stand/ring stand at the lab table or bench. b\. The, the distilling flask containing the mixture supported by a wire gauze below is placed on the hot plate, adjusting the universal/extension at its next to support the iron stand/ring stand. c. Later, the thermometer is placed with cork or cotton on the top of the distilling flask. d. Then another universal/extension clamp and clamp holder are adjusted to another iron stand/ring stand in order to fix the condenser. The condenser is adjusted to the second universal/extension clamp and must be fixed. e\. Next, the distillation adapter is mounted with a receiving container (50- or 100-mL Erlenmeyer flask), where the distillate is collected. f\. Finally, two rubber tubing are connected to a condenser to provide the water (inlet from water supply, lower end, and outlet to sink, upper end). ***Suggestion:** Search for the pictures or images of the distillation set-up to easily follow the above procedures.* 3\. Gently heat the distilling flask using the hot plate. Eventually, the liquid will boil, vapors will rise and enter the condenser, and liquid will recondense and be collected in the Erlenmeyer flask. 4. Discard the first 1 mL of distillate collected. Use a 10-mL graduated cylinder to measure the mL of the distillate collected. 5\. Record the temperature of the vapors as soon as another 1 mL of distillate has been collected (1). 6. Continue collection of the distillate until approximately one-half of the mixture has been distilled. Record the temperature of the vapors at this point (2). Turn off the hot plate and allow the system to return to room temperature. 7\. The distillate and the liquid in the distilling flask will be tested. a\. Place in separate clean, dry test tubes of 2 mL of distillate (test tube 1) and 2 mL of the residue liquid from the distilling flask (test tube 2). Add to each sample 5 drops of silver nitrate solution. Look for the appearance of a white precipitate. Record your observations. b\. Place in another separate clean, dry test tubes of 2 mL of distillate (test tube 1) and 2 mL of the residue liquid from the distilling flask (test tube 2). Obtain a wire loop and dip this into 4 mL of concentrated HCl solution and hold the wire in a Bunsen burner flame until the yellow color in the flame disappears. Dip the wire into the distillate sample (test tube 1). Put the wire into the Bunsen burner flame. Record the color of the flame. Repeat the above procedure, cleaning the wire, dipping the wire into the liquid from the distilling flask (test tube 2), and observing the color of the Bunsen burner flame. Record your observations. 8\. Take a picture of your output (Picture A) and make sure to also take a picture of your group with the This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ output (Picture B). Place these pictures in the DOCUMENTATION SHEET. **B. [Heating Under Reflux]** **Procedure:** 1\. Mix 10 mL of methyl salicylate (oil of wintergreen) with 100 mL of diluted 10% NaOH solution in a Florence/boiling flask. 2\. Assemble the heating under reflux set-up. a\. First, the universal/extension clamp and clamp holder are fixed to an iron stand at the lab table or bench. b\. Then, fill an enough water into the water bath. Place the water bath supported by a wire gauze on a hot plate. c\. Later, place the Florence/boiling flask containing the mixture in the water bath. d. Next, attach the condenser upright to the Florence/boiling flask placing the open end at the top. The condenser is adjusted to the universal/extension clamp and must be fixed. Be careful no vapor escapes. Plug the condenser at the open end with a stopper (cork or cotton). e. Finally, two rubber tubing are connected to a condenser to provide the water (inlet from water supply, lower end, and outlet to sink, upper end). ***Suggestion:** Search for the pictures or images of the heating under reflux set-up to easily follow the above procedures.* 3\. Heat and boil the Florence/boiling flask using the hot plate for 45 min. 4\. After heating and boiling, let the Florence/boiling flask to stand until it cools down to room temperature. 5\. Acidify the mixture with concentrated H~2~SO~4~ solution. Only use enough amount of conc. H~2~SO~4~ until the mixture acidifies. Use litmus paper to indicate its pH condition. 6\. Filter the precipitated compound. 7\. Wash the residue with water and let it dry between the filter paper after. 8\. Weigh the product after. The product is expected be salicylic acid. 9\. The product will be tested. a\. Reaction with Bromine water. Add approximately a small amount of salicylic acid to 2 mL of bromine water. Shake the mixture and note the color produced. Record your observations. b. Reaction with Ferric Chloride T.S. Use a pinch of salicylic acid and put in a watch glass, add drop per drop of FeCl~3~ T.S. until a color is produced. Record your observations. c\. Reaction with Methanol. Add at least 1 mL of methyl alcohol to an approximately small amount of salicylic acid. Note of the color and odor produced. Record your observations. 10\. Take a picture of your output (Picture A) and make sure to also take a picture of your group with the output (Picture B). Place these pictures in the DOCUMENTATION SHEET. This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **OBSERVATION SHEET** **A. [Distillation]** 1\. Temperature of vapor after collecting 1 mL of distillate \_\_\_\_\_\_\_\_ 2\. Temperature of vapor at the end of distillation \_\_\_\_\_\_\_\_ **Sample** **Observation with AgNO3** **Color in Flame Test** ------------------------------------------------------------- ---------------------------- ------------------------- Distillate (Distilled water) Theoretical Result: Theoretical Result: Actual Result: Actual Result: Liquid residue in the distilling flask (Salt-water mixture) Theoretical Result: Theoretical Result: Actual Result: Actual Result: 3\. Were you able to collect a pure distilled water? Explain why or why not. **B. [Heating Under Reflux]** **Reaction with Bromine Water** **Reaction with FeCl~3~ T.S.** **Reaction with Methanol** --------------------------------- -------------------------------- ---------------------------- Theoretical Result: Theoretical Result: Theoretical Result: Actual Result: Actual Result: Actual Result: 1\. Were you able to collect salicylic acid? Explain why or why not. This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ 2\. Why we use indirect heating or indirect evaporation technique for heating under reflux? 3. Why do we add H~2~SO~4~ to the reaction after it cools as opposed to when it is still hot? This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **DOCUMENTATION SHEET** **A. [Distillation. ]**Place the pictures needed in their designated boxes. **PICTURE A PICTURE B** **B. [Heating Under Reflux.]** Place the pictures needed in their designated boxes. **PICTURE A PICTURE B** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **ACTIVITY QUESTIONS** **Instruction:** Answer the following questions. **1. Draw the distillation set-up and label the apparatus/equipment involved. 2. Explain the principle and application of distillation.** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **3. Why is "distillation" a purifying technique?** **4. In a mixture, there is a volatile compound A and a nonvolatile compound B. Which compound would distill? Which compound would remain behind?** **5. You have a liquid that is heat-sensitive and decomposes when overheated. How can this material be purified by distillation without using excessive heat?** **6. What are the different types of distillation? Describe each.** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **7. What is the function of flame testing?** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **8. Draw the heating under reflux set-up and label the apparatus/equipment involved. 9. Explain the principle and application of heating under reflux.** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory** **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **10. Why heating under reflux takes time?** **11. Illustrate different types of laboratory condenser. Describe each.** This document is the property of **PHINMA EDUCATION** **CHE-005: Organic Chemistry Laboratory**  **Laboratory Activity Sheet \#4** Name: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Class number: \_\_\_\_\_\_ Section: \_\_\_\_\_\_\_\_\_\_\_\_ Schedule: \_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_\_ Date: \_\_\_\_\_\_\_\_\_\_\_\_\_ **References:** Coyne, G.S. (1997). *The Laboratory Companion: A Practical Guide to Materials, Equipment, and Technique*. John Wiley & Sons, Inc. Bettelheim, F.A., Landesberg, J.M. (2010). *Laboratory Experiments for Introduction to General, Organic, and Biochemistry* (7th ed.). Brooks/Cole, Cengage Learning. Seager, S.L., Slabaugh, M.R. (2010). *Safety Scale Laboratory Experiments for Chemistry for Today: General, Organic, and Biochemistry* (7th ed.). Brooks/Cole, Cengage Learning. This document is the property of **PHINMA EDUCATION**