PROCEDURE 1 Weigh out the metallic Cu and place it in a 250mL Erlenmeyer flask. Place the flask near the window and slowly and carefully add concentrated nitric acid. After adding the acid and when the gas begins to evolve, cover the flask with the gas trap stopper and allow the gas to drain into the KOH solution. When the gas stops coming out, and if all the copper is still not dissolved, add more nitric acid and repeat the operations until the Cu dissolves completely. NO2 is released, which is a very toxic reddish-brown gas, so it is important to "catch" it. PROCEDURE 2 Accurately measure the volume of the solution obtained in the flask in the previous reaction. Take a 10 mL aliquot and place it in a 250 mL beaker. Add approximately 30 mL of water and 5 mL of 6M NaOH. Allow the precipitate to settle and if the solution is not completely discolored, add a little more NaOH until discoloration is complete. PROCEDURE 3 Heat the sample until all of the precipitate turns to cupric oxide, which is black in color.
PROCEDURE 1
Weigh out the metallic Cu and place it in a 250mL Erlenmeyer flask. Place the flask near the window and slowly and carefully add concentrated nitric acid. After adding the acid and when the gas begins to evolve, cover the flask with the gas trap stopper and allow the gas to drain into the KOH solution. When the gas stops coming out, and if all the copper is still not dissolved, add more nitric acid and repeat the operations until the Cu dissolves completely. NO2 is released, which is a very toxic reddish-brown gas, so it is important to "catch" it.
PROCEDURE 2
Accurately measure the volume of the solution obtained in the flask in the previous reaction. Take a 10 mL aliquot and place it in a 250 mL beaker. Add approximately 30 mL of water and 5 mL of 6M NaOH. Allow the precipitate to settle and if the solution is not completely discolored, add a little more NaOH until discoloration is complete.
PROCEDURE 3
Heat the sample until all of the precipitate turns to cupric oxide, which is black in color.
PROCEDURE 4
Filter the black precipitate and wash it three times with 10 mL of water. Add 3M H2SO4 little by little and very carefully on the filter until all the precipitate reacts by dissolving.
PROCEDURE 5
To the previous solution add one or two zinc granules previously weighed and allow the reaction to complete. If the solution is still blue, add another little zinc previously weighed. It is important to know the total amount of zinc that I add. In this step, two
Write balanced equations for each of the reactions. Identify the substance that is oxidized and the one that is reduced in the reagents.
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