I weighed the filter to find out the mass. I then folded the filter and placed the filter into the funnel and held the funnel over a paper cup while I poured the liquid into the funnel leaving the benzoic acid to adhere to the filter. I then allowed the filter to dry. Once dried I weighed the mass of the filter and benzoic acid and calculated the mass and recorded into table 1. I then allowed the remaining liquid to evaporate leaving behind salt.
Reduction and Recovery of Copper Name Here March 18, 2015 Purpose: The goal of this experiment was to use redox chemistry to obtain a sample of copper from a copper (II) sulfate solution. This was accomplished by adding zinc to the copper (II) sulfate solution so that the zinc bonds to the sulfate and leaves copper. Method: To obtain copper from a copper (II) sulfate solution, the copper needs to go through reduction; this means another element has to go through oxidation. For this experiment, zinc was the element going through oxidation. First, we had to calculate how many grams of copper (II) sulfate we needed to form 100 mL of a 0.200 M solution of copper (II) sulfate.
* 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. * Filter the mixture by gravity filtration, washing the nutmeg residue with 10ml of diethyl ether. Evaporate the Ether from the filtrate * Recrystallize the product from ethanol. Filter using a Buchner funnel and wash them with cold water as shown in the diagram (see figure 2). * Let the crystals dry for one week, record the weight and take a sample and put into a glass capillary tube to obtain a melting point using the Melt-Temp machine.
Boil at least 10 minutes. 7. While the metal is still in the boiling water bath, measure the temperature of the boiling water carefully with a thermometer and record to tenths, one decimal place, in Data Table 2 8. After the metal has been heating 10 minutes, remove the metal from the boiling water bath using the string. Immediately transfer the metal into the calorimeter cup so that the water covers the metal.
Once all the water from the beaker was gone the clamp was carefully replaced so there were no air bubbles in the tube. The tube connected to the aspirator was then removed and connected to the test tube. The gelatin capsule was placed in the tube before adding 10 mL of HCl that had been measured in a graduated cylinder beforehand. The stopper was quickly and firmly placed into the test tube and the pinch clamp was removed again. After a few minutes the acid dissolved the capsule creating a black foam that then turned into a clear liquid again.
Stirred the mixture to make sure all soluble material dissolves. 10. Poured the liquid while it is hot into a small paper cup. 11. Poured another 10 to 15mL of distilled water into the beaker containing the sand, brining the mixture to a boil and decanted again into the same cup used previously.
After 5-10 minutes with the heat we started to observe a color change, after the CuSO4 (copper sulfate) cooled it had turned a grayish/ blue color. Using the electronic balance we weighed the CuSO4 with the crucible, which weighed 19.972 and subtracted the original weight of the crucible (19.972-19.071), which came to about .901, the weight of the leftover CuSO4. Heating to a constant mass is the only way to insure that the reaction is complete. It means checking the mass to ensure it is near each other at the end of a reaction. The color change in the copper sulfate when we heated it indicated that all of the water has evaporated, to be sure, we heated and weighed the crucible and CuSO4 again, and it came out to be .901g again.
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.