Obtain an Erlenmeyer flask that has a vacuum opening and attach the vacuum tube to it 8. Insert funnel and rinse the funnel with distilled water 9. Turn vacuum on and pour the pink solution into the Erlenmeyer flask, the precipitate should stay on top of the filter 10. Rinse the beaker out until all residue is gone 11. Try to rinse the precipitate in the funnel until the pink color is gone 12.
The aspirator was turned to medium high, and then the copper was poured onto wetted filter paper. Using distilled water to remove all copper from the beaker. Once completely on filter paper 6mL of acetone was added to the copper to help dry it out. The filter paper was then removed and set down to dry completely. Once dry the filter paper was weighed with the copper on it and subtracted from the original weight to see the amount of copper left after
The beaker was then moved to a stir plate with a stir bar and held in place by a ring stand. A funnel attached to an aspirator hose was fixed above to serve as a fume hood. With the aspirator and stir plate both on, 4.79 mL of 6 M HNO3 was added slowly to the beaker until the copper dissolved and the solution turned a light blue color. The hood could now be removed and 10.02 mL of distilled water was added to the solution. While stirring, 6 M NaOH was added drop-wise until the solution became basic, turning red litmus paper blue.
Wait for the bubbling to subside between additions so that the reaction does not overflow the flask. 6. When all the acetic acid has been added, swirl flask or stir for two minutes with a glass stirring rod. 7. When the solution is completely calm, move the flask to a hot plate and heat it to boiling.
Gently stir the pellets until the acid is dissolved by shaking the the apparatus. Lift the calorimeter lid and wash out its contents and the thermometer. Repeat this experiment using 50.0 mL of 1.0M acetic acid. Repeat experiment using 25.0 mL of each 2.0M sodium hydroxide and 2.0M acetic acid. Data Table(s): Reaction equation Mass of solid NaOH Initial Temp.
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. Then, centrifuge it for 1 minute. On the side, weight a boiling test tube containing 2 boiling chips. When the separation is complete, remove the small test tubes from the centrifuge and decant the supernatant into the boiling test tube. Add 1 mL of deionized water to the small test tube containing the precipitate and mix it and centrifuge it for 60 seconds.
We didn't make any mistakes. Possible errors we could have made throughout the lab would be: not letting the water fully evaporate, not measuring properly, burning the mixture, or even being careless and not doing things in order and as it was said. Discussion of Sources of Error- Our percent yield number was 99.1%. As I had said, we did everything pretty accurately with no major mistakes. It is possible that when we weighed the copper, it could have not been fully dry.
Nest one Styrofoam cup in another 11. Obtain an exact mass of tap water (45-50g) to serve as cold water 12. Put a magnetic stirrer in the bottom of the calorimeter 13. Secure temperature probe to a ring stand 14. Place temperature probe through hole in cardboard lid and position probe about 1cm above bottom of calorimeter 15.