The Copper Cycle Lab Technical Abstract Danielle Williams*Mauro Acosta, Kristen KoppalChemistry 111 Section 506IntroductionIn this lab experiment, the components of copper in a 5 step reaction were studied. The Law of Conservation of Matter is tested, as well as the varied uses of copper and how it can react with different compounds and elements. The purpose of this experiment simply put, is to show what isput into a reaction, can be taken out somehow. A reactant can become a product, and vice versa, but it all depends on the methods to obtain it. Materials and MethodsIn this experiment, there were multiple sections dealing with copper that correlated with each other. Before starting the full experiment, a set up was needed to be conducted. The set up required obtaining a ring stand and connecting a hot ring to it. Then a 50 mL beaker was placed on the hot plate and a funnel was clamped to the stand above it. The funnel was connected to a hose and aspirator to successfully create a fume hood. In Cycle Step One, 250 milligrams of copper were weighed and placed into the 50 milliliter beaker. Next, 5 milliliters of 6M HNO3 was measured into a 10 mL graduated cylinder. The water aspirator was turned on and the 6M HNO3 was added gradually, and observations were recorded. Cycle Step 2 involved removing thefume hood and adding 10 milliliters of distilled water into the beaker. Then drop by drop, 6MNaOH was added, stirred, then tested on litmus paper until the paper turned blue. Observations were again recorded. In Cycle Step 3, solution was heated and stirred, then observations were noted. The solution was then heated for 5 minutes then cooled. Cycle Step 4 required adding 10 more milliliters of distilled water, then 9 milliliters of 3MH2SO4 gradually drop by drop. It was then cooled to room temperature. Next was Cycle Step 5, which comprised of adding 5 milliliters and putting the mixture once again on the hot plate. A magnetic stir bar was added, as well as 300 milligrams of 20 mesh zinc. The stir bar was removed after observations were made, and the liquid was disposed properly, and 5 milliliters of 6MHCl was CHEM 111, Experiment 3 Technical Abstract, Fall 2016 Page 1 of 3added to react to extra Zinc. After all the cycle steps were completed, the Copper Recovery portion of the experiment was started. The remains of the mixture were rinsed with distilled water, and a vacuum filtration apparatus was created using a hose, flask, and aspirator. A Buchner funnel was added to the top of the apparatus, and then a piece of filter paper. Next, the water aspirator was turned on, and the paper was wetted with distilled water. The mixture was then transferred into the funnel, and washed with distilled water, and left to dry. Then the copper was weighed with a watch glass. Masses and observations were recorded and then contents were disposed in the proper containers. Results and DiscussionThis experiment was created in order to observe the various chemical reactions of copper, and how they affect each other in chronological order as the experiment progressed. The initial copper obtained had a mass of 250.9 milligrams. Because Copper is a transition metal, it was observed as malleable and shiny. The first cycle included the chemical equation of Cu(s) +HNO3 Cu(NO3)2 (aq) + NO2(g) + H2O(l). This was an example of a decomposition reaction, and the observations recorded revealed the substance bubbling, turning blue, leaving a yellow oxidation, and the copper was completely dissolved. This proves the equation above showing the reaction created a gas, liquid, and an aqueous solution with the copper. When the distilled water was added to continue onto cycle step 2, it remained to have the blue color from the initial reaction. However, the addition of the 6MNaOH created a double displacement reaction in the mixture, and solid crystals formed. There was a prominent color change as well, with the mixture changing from green, to yellow, to blue, and formed into a solid jelly-like substance. The chemical reaction for Cycle 2 was Cu(NO3)2(aq) + NaOH(aq) Cu(OH)2(s) +NaNO3(aq), showing theresult of the solid formation. Cycle 3 resulted in another decomposition reaction, represented by the chemical equation Cu(OH)2(s) CuO(s) + H2O(l). As this reaction occurred, solid specs appeared and the mixture became very dark, almost black. This reaction was quickened by the use of thermal energy, revealing the need for a catalyst like temperature to make the reaction work. H2SO4 was added in order to progress to cycle 4, thus creating the double displacement chemical equation CuO(s) + H2SO4(aq) CuSO4(aq) +H2O(l). Adding this chemical to the mixture with heat as a catalyst, created a very interested color change of blue to green, to back to blue. Finally, Cycle 5 included the addition of mesh Zinc. The measured mass of the mesh Zinc was CHEM 111, Experiment 3 Technical Abstract, Fall 2016 Page 2 of 3299.5 milligrams. The final chemical reaction was a single displacement equation which was CuSO4(aq) + Zn(s) Cu(s) + ZnSO4(aq). Once the rest of the Zinc and liquid had been disposed, all that was the left was the copper that was the filtered with the vacuum. The weight of the filter paper, copper, and watch glass was 52.0428 grams. The filter paper was weighed at 336.6 milligrams, and the watch glass was weighed at 50.8300 grams, which resulted in the copper mass equaling around 876.2 milligrams. This created a 71.36% error, and was most likely causedby improper measuring, human miscalculation, etc. The large percent error could have also been caused by a lack of time to thoroughly dry the filter paper, resulting in a measured weight of bothwater and copper, not just the copper itself. At some points in the experiment there were a couplevariances in the number of reactants added into the reaction, and might have cause an unbalancedreaction, causing issues down each cycle step. ConclusionAccording to the Law of Conservation of Matter and Energy, energy can neither be created nor destroyed, it can only change forms. This experiment proved that what can be put into a reaction can be taken out as well. Even though our results had some errors, it was still a successful experiment, and showed that in a chemical reaction, certain compounds and elements change form. They do not just disappear or get destroyed, but combine with different elements and compounds, and can result in millions of products that can impact
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