chemsample-lab1-methods

Conducted by: Robert Theis and Julia Valentino
 * __Microscale Dehydration of Cyclohexanol (Using Glassware with Elastomeric Connectors) -Regular Quantities__**

Assemble the distillation apparatus in figure 6. Note the minor changes in equipment - instead of using the 5mL round flask, use the 5 mL flat bottom flask. And, instead of the 100 mL beaker, use of a smaller beaker (50mL). Also, obtain a shorter, different styled air condenser to apply as your condeser.
 * Procedure:**

Obtain 1.5mL 85% H3PO4, 1.422g cyclohexanol, and add them to the flat bottom flask. Then add approximately 3 drops of H2SO4. After this is complete, add the magnetic stirrer, turn on the heat, and the magnetic stirrer to follow. Add flask to the distiller and position it within the sand bath so it is imbedded halfway. Now, you will begin your distillation.

The distillation process will take about 25 minutes, although you will know when it is fully distilled - when it reaches 85 deg/C. When (and if) it reaches this temperature, turn off the heat, turn off the magnetic stirrer and allow the mixture to cool.

You will know when the cooling process is complete, because within the receiver vial will have formed two layers. The layer that is important is the top one (your "Organic layer"), containing the cyclohexene product. You want to remove the bottom layer with a pipette and find a way to properly dispose of it.

Now you will add 0.25g anhydrous Calcium Chloride to your cyclohexene product in order to dry it. Obtain a sample vial, weigh it, record that value, and then add your cyclohexene to it - weigh it once more with the product in the vial. The difference between these two masses is the amount of cyclohexene produced from your distillation of cyclohexanol.

You will obtain a spot plate and place 5 drops of Ammonium Cerium (IV) Nitrate and 3 drops of 1,4-dioxane into three wells. To the first well add 2 drops of cyclohexanol. Stir, and then observe - look for things such as color change and/or solubility. Record your observations.
 * Product Characterization #1: Ammonium Cerium (IV) Nitrate Test**

To the second well add 2 drops of stock cyclohexene solution, stir, and again wait to see if there is a color change. Record your second observation(s).

To the third well add 2 drops of your product (cyclohexene), and again, stir, and look for color change and/or solubility. Record your observations.

First, label three small test tubes with the following: cyclohexanol, cyclohexene, and product. Place 2 drops of cyclohexanol into the test tube labeled “cyclohexanol”.
 * Product Characterization #2: Bromine test**

Next, add 2 drops of cyclohexene into the test tube labeled cyclohexene.

Next, place 2 drops of your product into the test tube labeled product. After those three wells have been filled, add 20 drops of dichloromethane to each test tube, and stir.

Finally, add the Bromine to each test tube and stir. Make sure to record any color change or observation in your lab notebook.

Conducted by Jaidalyn Rand-Ousley & Liz Wasil
 * __Semi-Microscale Dehydration of Cyclohexanol__**

Assemble the distillation apparatus seen in figure 5 on page 21.
 * Procedure:**

Next, put 4.02 mL 85% Phosphoric acid, 3.05 mL cyclohexanol, 5 drops of concentrated sulfuric acid, and a magnetic stirrer in the round bottom flask. Reattach this to the distillation apparatus and start water flow. Turn on the magnetic stirrer and heat the apparatus. Collect the distillate in the receiver flask until no more liquid distills or until the apparatus reaches 85°C.

When it reached 85°C, the hot plate was turned off and the apparatus was allowed to cool. The magnetic stirrer was turned off as well and the distillate was transferred to a smaller test tube. When the distillate settles remove the bottom layer and put it into a separate labeled beaker "Recovered Acid Layer".

Put 0.2488 g anhydrous calcium chloride into the test tube and let it stand for 5 minutes. Next weight of a sample vial was taken, with a recorded the mass of 6.163 g. The product was put in the vial and weighed at 7.254 g, resulting in 1.091 g of product.

1. Add 5 drops of monium Cerium (IV) Nitrate and 3 drops of 1,4-dioxane into three wells. Add 2 drops of cyclohexanol to well 1, stir, and observe changes. Add 2 drops of cyclohexene to well 2, stir, and observe. Add 2 drops of product in well 3, stir, and observe. Record observations and characterize.
 * Product Characterization:**

2. Label three small test tubes with as follows: cyclohexanol, cyclohexene, and product. Place 2 drops of cyclohexanol into the test tube labeled “cyclohexanol”. Next, add 2 drops of cyclohexene into the test tube labeled "cyclohexene". Also add 2 drops of product in the test tube labeled "product". Now add 20 drops of dichloromethane to each test tube and stir. Now add the Bromine to each test tube, stir, and observe. Record any color change or observations in your lab notebook.

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__**Microscale Dehydration of Cyclohexanol (Using Glassware with Elastomeric Connectors) – Double Quantities**__ ===== ** 1.) Using Distillation to Dehydrate Cyclohexanol Assemble the distillation apparatus shown in lab protocol. Remove the 10mL round-bottom flask from the apparatus. Place 3.0ml of 85% H 3 PO 4 and 2.844g of cyclohexanol into the flask. Add 6 drops of concentrated H 2 SO 4 to the flask and add a magnetic stir bar. Reattach the round-bottom flask to the distillation apparatus. Turn on the magnetic stirrer. Heat the reaction mixture while stirring until the product starts to distill. Continue the distillation, collecting the product in the receiver vial until no more liquid distills or until the temperature of the thermometer rises above 85°C. Turn off the heat. Allow the apparatus to cool. Turn off the magnetic stirrer. Remove the receiver vial from the distillation assembly. Use a Pasteur pipet to transfer the distillate into a centrifuge tube or small test tube. **

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2.) Isolating Cyclohexene ======

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Dry the top organic layer by placing about 0.25g of anhydrous calcium chloride in the test tube. Let the test tube stand for 5 minutes. Weigh a clean 5mL sample vial. Using a clean dry Pasteur pipet, remove the liquid from the tube and transfer the liquid to the tarred sample vial. Weigh your product. Characterize your cyclohexene. ======

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3.) Cleaning Up ======

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Place your recovered materials in the appropriate labeled collection containers as directed by your laboratory instructor. Clean your glassware with soap and acetone. Wash your hands thoroughly. ======

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