5 mL of 6 M HNO3 was added in beaker to react with copper. Secondly, after 10 mL of distilled water was added, 6 M NaOH was added drop wise until the drop of solution turned red litmus paper blue. Thirdly, the solution was heated with 200 degree until reaction occurs. The reaction mixture cooled to room temperature after continued heated for five minutes. Then, 10 mL of distilled water was added to the precipitate.
The mixture was decanted again in to the same beaker. Next, we added boiling chips to the liquid and evaporated the solvent over the hot plates under the hood. After the solvent was evaporated and the flask was cooled, we used a spatula to remove a small amount of the crude product and took its melting point. We determined the melting point range of the sample to be 43.0-46.0 degrees Celcius.The crude product was yellow colored when it was warm and orange in color when cooled and sticky. We then recrystallized our sample using 5 ml of warm acetone that was heated on a hot plate under a hood.
Fill the calorimeter cup approximately 2/3 with distilled water at room temperature and record the mass in Data Table 1 5. Measure the temperature of the tap water in the calorimeter cup and record in Data Table 2. 6. Carefully transfer the metal to the beaker with boiling water. Boil at least 10 minutes.
The 15 M NH4OH was added drop wise until a color change occurred, or until 20 drops were added. An additional 10 drops of 15 M NH4OH were then added to each solution. Again, 5 centrifuge tubes were labeled for the same 5 cations and 20 drops of each solution were added to the appropriate centrifuge. HCl was also added to a 50 mL beaker. The Nichrome wire loop was dipped in the HCl solution and placed over the Bunsen burner to disinfect it.
After a few minutes the acid dissolved the capsule creating a black foam that then turned into a clear liquid again. Once the liquid was clear again, the clamp was closed and the beaker was weighed. The temperature of the water was also taken. This was then repeated again for Trial 2 with a new capsule. Specialized Chemical Techniques: The specialized technique used in this experiment was
The pH recorded by using pH electrode before adding NaOH. The solution titrated by 2 ml of NaOH each time and the pH recorded until the color change. These steps were done for the two known solutions and the unknown solution. Part 2 10 ml of vinegar placed in 100ml volumetric flask and deionized water added until the mark. The solution transferred in 150 ml beaker labeled as beaker #1.
Extraction and Drying: Using a separatory funnel, the cooled filtrate was extracted with 10ml of methylene chloride. After shaking our mixture, we broke and dried our emulsion by slowing passing the lower layer through a cotton ball layered with anhydrous magnesium sulfate. The extraction process was repeated 2 more times for maximum collection of the organic layer. Distillation: The extracts were poured into a 50ml round bottle flask and connected to a simple distillation apparatus. To obtain the caffeine, the methylene chloride was removed from the extract, leaving us with our solid caffeine residue.
A melting point will be ran on the aspirin when completely dry. A capillary tube containing the dry aspirin will be placed into the melting-point apparatus. This process is to determine the melting point range of aspirin. First, a hot water bath was created with a 400. mL beaker on a hot plate. The temperature was raised to 70 degrees Celsius and 4.419 g of salicylic acid was measured out on a balance and transferred into a 125. mL Erlenmeyer flask.
Transfer the extracts to a simple-distillation assembly and distill off all but 10 mLof the solvent on a steam bath. Save the recovered solvent. Evaporate the combined solutions to dryness on a steam bath or hot-water bath in a hood. To purify the crude product, dissolve it in about 5 mL of acetone by warming the mixture on a steam bath; add dropwise just enough mixed “hexanes” to turn the warmed solution faintly cloudy; then allow the solution to cool and allow the product to crystallize. Collect the green-tinged crystals on a small vacuum filter and wash them with a little mixed “hexanes.” The melting point of caffeine reported in the literature is 236°.
Allow the crystals to dry for 1 week then, weigh it, take a MP, and calculate the % yield. * Assemble the apparatus for reflux using the diagram (see figure 1), place boiling chips or a stirring bar in the bottom of the flask. * Weigh 2grams of finely ground nutmeg and combine with 10ml of diethyl ether in a 50ml round bottom flask. * Place a heating mantle under the round bottom, turned on and the heat was slowly adjusted until the mixture starts to boil for 45minutes, then let cool to room temperature by sitting it on the lab bench. * Pour a little ether over the nutmeg residue on the filter paper so that any Diethyl ethanol traces clinging to it is washed down and mixed with the filtered liquid underneath.