Organic Chem. Lab EXPERIMENT 11: ISOLATION OF CAFFEINE FROM TEA LEAVES COMPOUND PROCEDURE Preparation of Tea Solution: We started out experiment by weighing out 5.023g of tealeaves and 2.008g of calcium carbonate powder. These two substances were mixed with 50ml of water and heated under gentle reflux in a round-bottom flask using a condenser apparatus. The hot solution was then filtered and the filtrate was collected and cooled. Extraction and Drying: Using a separatory funnel, the cooled filtrate was extracted with 10ml of methylene chloride.
We then recrystallized our sample using 5 ml of warm acetone that was heated on a hot plate under a hood. The warm acetone was poured in to the beaker with our crude sample and swirled. The beaker with our sample was then placed in to an ice bath to cool and
I then poured the mixture on to a solid white piece of paper. I then used a magnet wrapped in clear plastic bag to separate the iron from the mixture. I weighed the iron and calculated and recorded the mass in table 1. I put the remaining mixture in a beaker with 50 mL of distilled water and heated to a boil and removed, then poured the liquid from the beaker into a paper cup. I then added 15 mL of distilled water and heated to a boil and removed, then poured the liquid from the beaker into the same paper cup that held the previous liquid.
Success of this technique was measured by finding the recovered mass of caffeine. Procedure In a 500-mL Erlenmeyer flask, place 30 g of ordinary dry tea, 300 mL of water, and 15 g of powdered calcium carbonate. After boiling the mixture gently for 20 min, occasionally swirling it, add 5 g of Celite or other filter aid, filter the hot mixture in a Buchner funnel, and press the filter cake firmly with a large cork to obtain as much of the liquid as possible. Cool the aqueous extract to 15-20C, transfer it to a separatory funnel, and extract the caffeine with four successive 25-mL portions of dichloromethane. Transfer the extracts to a simple-distillation assembly and distill off all but 10 mLof the solvent on a steam bath.
With increasing temperatures the solute can be dissolved by a solvent during recrystallization. Experimental section Preparation of Chalcone To prepare chalcone 2.1mL of NaOH in was dissolved in 40mL of water and about 25mL of ethanol was added in a 125mL Erlenmeyer flask as soon as pellets were dissolved. Then 0.080 mole of acetophenone was stirred into the 125 mL flask, then place into an ice bath. At once 0.080 moles of bezaldehyde was added to the mixture and stirred all the while temperature was kept between 20-30°C. A stopper was placed on the flask while the mixture was stirring with stirrer for 11/2 hours.
While the water was sitting, I put each portion of beet into individual beakers and began to test each portion individually. For tests 1-4 I soaked each piece of beet in water warmed to it’s corresponding temperature for one minute. I then removed the beet from the water and placed it back into its beaker then added 3ml of the room temperature tap water. I then let it sit for 20 minutes. For test 5, I placed the dry beet in its beaker and put it into the refrigerator for 30 minutes, removed it, and added 3ml room temperature tap
Second, methyl benzoate is added to form a new carbon-carbon sigma bond. The intermediate magnesium alkoxide will then be hydrolyzed to form tertiary alcohol product. Experimental Procedure: Part A: Preparing the Grignard reagent • I placed 1.98 grams of magnesium turnings into a cleaned 250mL round-bottom flask and then attached the calcium chloride drying tube into the round-bottom flask • Then, I placed this flask onto a heating mantel and adjust the controller to setting ‘6’. This flask is heated until it was too hot to touch. • After the flask was heated, I removed it from the heating mantel and allowed it to cool to room temperature.
8. Placed the remaining mixture, containing sand, benzoic acid and table salt into beaker and added 50mL of distilled water. 9. Set up the beaker stand and burner fuel and heated the beaker of solids and water to near boiling. Stirred the mixture to make sure all soluble material dissolves.
You will need a 10 ounce bag of miniature marshmallows, a 2 pound bag of confectioner’s sugar, 3 tablespoons of water, a large spatula, a large microwaveable bowl, some shortening, plastic wrap, and a rolling pin. First you need to empty the bag of miniature marshmallows into the large bowl and pour the 3 tablespoons of water over the marshmallow. Place the bowl in the microwave for one minute to melt the marshmallows. When it is done remove the bowl and stir the marshmallow. If the marshmallows are not all melted return the bowl to the microwave for 30 seconds at a time until they are completely melted, remembering to stir the marshmallows each time.