Chem. 317 Title: The Synthesis of Chloropentaamminecobalt(III) chloride and Linkage Isomerization to Further Synthesis Pentamminenitrocobalt(III) chloride Experimental: Ammonium chloride (.0467 mol) was diluted in concentrated aqueous ammonia (15 ml) in a 125ml Erlenmeyer flask. CoCl26H2O (.0210 mol) was then added to the ammonium chloride solution. The ammonium chloride solution was heated and stirred while 30% hydrogen peroxide (4 mL) was added drop wise. The reaction was monitored and removed from the heat once the effervescence ceased, and then was allowed to cool.
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.
Procedure: 1. Fill a beaker two-thirds full of water and add approximately 20 drops of IKI. Write down the solution's color and record the mass of the bag. 2. Do an initial Benedict's test on the 15% glucose/1% starch and the beaker solutions for glucose by putting some of the solution and a roughly equal amount of blue Benedict's solution in a test tube, placing the test tube in boiling water for 90 seconds, and observing whether or not the solution changes color from blue.
Then, I filled the tube to the shoulder with distilled water. I added one nitrate tablet. I capped the tube and I mixed until the tablet disintegrates. I wait 5 minutes for the color to develop. Then I compared the blue color of the solution to the nitrogen color chart: L = 40 lbA/6" soil, M = 160 lb A/6" soil, and H = 320 lb A/6"
Part A: Spectroscopy 1. 0.05g of Iron(III) Nitrate in a 50-ml beaker. Add 17 mL of distilled water to the beaker and mix with a stir rod until the solid is completely dissolved. 2. Obtain another 50-mL beaker and add 0.05g of Chromium(III) Nitrate to the beaker.
Add a quarter spatula of copper (II) oxide and warm the solution gently to the 4th test tube and record observations. 7. To the 5th test tube, add 3cm3 of ethanol a couple of drops of conc, sulphuric acid and warm gently. Pour the resulting mixture into 30cm3 of sodium carbonate solution to remove excess acid and smell and record observations. Experiment 2 Time | Observations | 5 minutes | Bubbled like sugar | Once salt water was added | Turned soapy white and thick | Equation: METHOD 1) Put 2 cm3 of castor oil into a 250 cm3 beaker and add 10 cm3 of 5mol.dm-3 sodium hydroxide from a measuring cylinder.
Procedure 2.0ml of 1-bromobutane, 2.97g of sodium benzoate, 5.0ml of water and 4 drops of Aliquat 336 were placed into a 50ml round-bottomed flask. The mixture was underwent reflux for 1 hr at around 120oC. The mixture was cooled to the room temperature. 10ml of distilled water was added into the flask to dissolve the solid. The mixture was transferred to a separating funnel.
3. The mixture was poured into a beaker containing 25cm3 of ice – water and 2.5cm3 of concentrated HCl. Reaction mixture was left in ice – bath for 10 min. 4. Precipitated product was recovered by vacuum filtration and washed with two portions of 5 cm3 of ice – cold water.
Then, 3.4 g of ammonium sulfate was slowly added to the supernatant 1 as it was stirred for 15 min to achieve 50% saturation (85g/L of solution). The supernatant was then centrifuged at 9000 x g and 40C for 15 min and 5 ml of the second supernatant was transferred to a conical tube. The obtained second pellet was resuspended in 4 ml of distilled water and transferred into another dialysis
The experimenter used 3 identical plastic cups and filled one with room temperature tap water, one with warm tap water and one with boiling tap water. Each cup was placed into the freezer and was checked every 15 minutes for signs of freezing. The experimenter found that the room temperature water showed the first signs of freezing and in the final outcome froze solid before the water in the other cups. His findings showed that water containing impurities, such as tap water, will freeze faster based on a lower starting temperature. The second case study was covered in an article by Science News.