Record the mass of thyme used. 2. Using a measuring cylinder, add 50cm3 of 1.0mol dm-3 sulphuric(VI) acid and boil gently for 5 minutes. 3. Allow the mixture to cool for a few minutes then filter it, using either gravity or vacuum filtration.
After that, dissolve the sample in 2 mL of deionized water and shake the test tube for 1 to 1 ½ minutes to dissolve the solid. Place another dry test tube in a 50mL beaker and weigh it. Find a bottle of barium iodide and record the name and molar mass. Then, weight out either anhydrous barium iodide or barium iodide dehydrate into this test tube and dissolve is it in 2 mL of deionized water. Pour the contents of one of the test tubes into the other and a reaction should occur and you should see a white precipitate of barium sulfate form.
SYNTHESIS 3 Purifying an unknown solid by recrystallization involved preparing cobalt amine chloride product. By adding five grams of cobalt II chloride into 20ml of 9M HBR in 250 mL beaker, plus 15 mL of deionized water. Dissolving the compound within pure water, filtration by gravity and adding two grams of activated charcoal and 25 mL of concentrated. Cooled after heating and additional six mL of 30 percent hydrogen peroxide. Filter by suction then collect the dark solid.
b. Once again, place assembly in water bath and begin to heat c. When acetamide has begun to melt, record the temperature. d. Let assembly cool down and record temperature when acetamide begins to recrystallize. e. Repeat process two more times. Data: Data Table 1 | | | Rubbing Alcohol Trial # | Boiling Point | Percent Error | 1 | 79.5 C | 3.52% | 2 | 84.0 C | 1.90% | 3 | 83.5 C | 1.30% | Data Table 2 | | | | Acetamide Trial # | Melting Point | Freezing Point | Percent Error (Melting Point) | 1 | 79.5 C | 57.5 C | 3.50% | 2 | 80.5 C | 59.5 C | 0.60% | 3 | 78.0 C | 61.0 C | 3.70% | Observations: It was observed that thermometer placement could affect the readings in the water bath.
Obtain another 50-mL beaker and add 0.05g of Chromium(III) Nitrate to the beaker. Then, add 17 mL of distilled water and mix until the solid is dissolved. 3. Obtain a final 50-mL beaker and add 0.05 grams of the unknown substance to the beaker. Add 17 mL of distilled water and mix with a stir bar until the solid is completely dissolved.
Then 5mL of HCl was added to copper to completely remove all traces of zinc. Once the bubbling had stopped, the rest of the liquid was decanted away from the copper. Then the copper recovery set up was put together using tubing, Buchner funnel, filter paper and suction flask. Then the filter paper was weighed before placing it in the funnel and wetted down. The aspirator was turned to medium high, and then the copper was poured onto wetted filter paper.
Next, obtain a 5 mL serological pipet and thoroughly rinse it with the buffer solution, then discard the buffer solution into the 250 mL beaker. Now, use the pipet to distribute 5 mL of the buffer solution into three 50 mL beakers. Be sure that the 50 mL beakers have been cleaned are dried prior to this. Next, locate the three pre filled burets in the lab room. Find the buret labeled 1.0M HCl and add exactly 1.00 mL of HCl to just one of the three 50 mL beakers with buffer solution already in them.
Using another 125-mL flask, 60-mL of 0.3622 M potassium hydroxide in ethanol was deposited. Both flasks were clamped in a temperature-controlled bath regulated at 50.0˚C. The solutions were then set in the temperature bath for ten minutes to equilibrate. An empty 250-mL Erlenmeyer flask was also clamped in the same water bath. In another flask 50-mL of ice water was deposited with three-drop phenolphthalein.
Transfer the distillate via Pasteur pipet into a 15-mL centrifuge tube. Wash the distillate with two 2.5-mL portions of water, removing and setting aside the water layer at each step. Transfer the organic material to a small, dry Erlenmeyer flask, leaving behind the last drops of the water layer. Remove any drops of water that were accidentally transferred to the Erlenmeyer flask, if any, then add small amounts of anhydrous sodium sulfate as drying reagent. When the liquid is dry, it will be transparent and some of the drying agent will flow freely like beach sand.
Compare the MPs of the once recrystallized and the twice recrystallized trimyristin. After the hydrolysis has proceeded for 45 minutes, allow the flask to cool to RT and pour the contents into a 50 mL beaker containing 8 mL of water. Carefully, in the hood, add dropwise with stirring, 2 mL of concentrated HCl (caution: corrosive liquid/noxious vapors). Myristic acid should precipitate. Cool the beaker in ice water for 10 min, with stirring, and collect the solid by vacuum filtration on a small Hirsch funnel.