The filtrate will then be added to concentrated hydrochloric acid After the

The filtrate will then be added to concentrated

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charcoal. The filtrate will then be added to concentrated hydrochloric acid. After the addition is complete, you will chill the solution and filter the precipitate under vacuum filtration. Chilling the solution will lower the solubility of the precipitate and increase the yield. Detailed Procedure Borrow a magnetic stir bar from the store window (Bring your student ID card). From a dispenser or common burette, take 10 mL of the cobalt(II) chloride solution into a 125 mL Erlenmeyer flask. Carefully add the magnetic stir bar to the flask. Add 1 g of activated charcoal (contents of one vial, you do not need to weigh) to the solution. Verify that the vacuum line is working properly. The water trap must be 2/3 filled with tap water. Ask your TA if you are not sure. Prepare a large cotton plug to fit into the mouth of the Erlenmeyer flask, it should fit closely but not too tight. The plug will prevent ammonia fumes from escaping into the lab without tightly sealing the flask. Take the flask and cotton plug to the ammonia dispenser, and add about 5 mL of concentrated ammonia directly into the cobalt chloride solution. Quickly replace the cotton plug and record your observations in Table 1 of the data sheet. Clamp the reaction flask to the stand of the hotplate so that the flask sits on the plate's surface, but do not turn on the hotplate yet. Stir the solution such that the magnet spins smoothly without splashing the solution all the way up the side of the flask. If, [Co ] ( O) H 2 6 + 2 H 2 O 2 Co 2 + Co 3 + H 2 O 2 Safety Warning Fumes from ammonia and hydrochloric acid are present in this experiment. Follow instructions carefully and work in a fume hood or under an aspirator arm. "
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11/8/19, 1’06 AM Coordination Compounds Page 15 of 23 at any point, you detect (smell) ammonia fumes coming out of your flask, cap the flask with your cotton plug and bring it to the nearest fume hood. Clamp the separatory funnel to the stand, well above the reaction flask, and prepare a collar of cotton to be placed around its stem. Lower the separatory funnel into the mouth of the flask and loosely put the cotton collar around the funnel stem, as in Figure 3. Measure about 10 mL of 7.5% hydrogen peroxide ( ) from a common burette in the fume hood into a clean, medium sized test tube. Ensure the separatory funnel stopcock is in the closed position. Pour the into the separatory funnel. Open the stopcock partially so that the is slowly added to the flask – you want a slow but steady series of drops, not a stream. Continue the stirring during the addition in order to aid the oxidation of the to . When all of the has been added, remove the separatory funnel from the flask and clamp it turned away from the Erlenmeyer flask.
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