AP Chemistry
12/13/11
Round-Trip Copper Reactions Lab
The purpose of this lab was to evaluate our skills of decanting a supernatant liquid without losing the solid and successful completion of a series of reactions. This was done through five chemical reactions involving copper. In this lab, elemental copper was put through five different chemical reactions in order to convert it into different compounds. By the end of the fifth reaction, the copper was back to its elemental state. In the first reaction, 0.95 g of pure copper was reacted with 4.0 mL of concentrated nitric acid under the fume hood. The solution was swirled until all of the copper had dissolved. The balanced equation for this reaction is as follows:
Cu (s) +
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The black precipitate was allowed to settle and then the supernatant, the clear liquid that lies above a precipitate, was decanted, or poured carefully off. Then, 200 mL of hot distilled water was added and the precipitate was allowed to settle to repeat the decanting process again. In the fourth reaction, 15 mL of 6.0 M sulfuric acid was added to the copper (II) oxide while stirring. The balanced equation for this reaction is as follows:
CuO (s) + H2SO4 (aq) à CuSO4 (aq) + H2O (l) + SO2 (g)
When the sulfuric acid was added to copper (II) oxide, the solution turned blue. This was due to the formation of aqueous copper (II) sulfate, which produced the copper ions to change the color of the solution. In the fifth reaction, 2.29 g of zinc was added to the copper (II) sulfate solution under the fume hood. The balanced equation for this reaction is written as followed:
Zn (s) + CuSO4 (aq) à ZnSO4 (aq) + Cu (s)
When the zinc was added to the copper (II) sulfate solution, the solution started to bubble. As the solution was stirred, it turned a cloudy blue. Small flecks of a brown solid were visible. As the solution became colorless, the brown solid settled to the bottom of the beaker. The solid formed was copper in its elemental state. The color faded from the solution as the copper ions slowly formed into solid copper. The copper was poured into a funnel with filter paper and washed three times with 25 mL
It is a chemical reaction where the colors of both solution and iron strip changed. It is
The purpose of the experiment is to cycle solid copper through a series of five reactions. At different stages of the cycle, copper was present in different forms. First reaction involves reaction between the copper and nitric acid, and copper changed from elemental state to an aqueous. The second reaction converted the aqueous Cu2+ into the solid copper (2) hydroxide. In the third reaction Cu(OH)2 decomposed into copper 2 oxide and water when heated. When solid CuO reacted with sulfuric acid, the copper returned to solution as an ion (Cu2+). The cycle of reactions was completed with the reaction where elemental copper was regenerated by Zn and Cu
Washing of the copper is necessary in this experiment to separate the iron from the copper and make sure the iron is not counted in the mass of the copper.
Obtain a 50 mL beaker for the experiment. In the first part of the experiment, you dissolve the zinc core of a penny and leave the copper covering intact by putting four notches in
The Cu Later lab experiment is designed to allow you to practice lab skills in implementing and performing a series of reactions. Specifically, four types of chemical reactions will occur: oxidation/reduction; double replacement; single replacement; and decomposition. You will begin with a known amount of copper metal, which, after progressing through several steps, is reproduced. In this experiment you will observe and record the various changes such as heat, color changes, and production that occur. This procedure is used to observe some chemical reactions of copper and its compounds while also performing the lab appropriately as to retain the copper as much as
Then 8.0g of copper sulfate crystals were placed inside the beaker and the mass was recorded for the actual crystals. 50 mL of water was added to the beaker with the crystals. The ring stand was set up with the wire mesh on it and one partner should place the mixture in the beaker on it should be heated without letting the mixture boil. Stir the mixture and heat until the crystals are dissolved. While one partner does this, the other should obtain 1.5g of iron filings in a measuring cup and records the mass. Then the iron filings should be added small amounts at a time to the heated solution. Stir continuously until all the mixture is added to the beaker. Then it sat for 10 minutes and observations were recorded. Record the mass of a filter paper and set up a filtration apparatus with the filter paper in a funnel over an Erlenmeyer flask. Decant the liquid through the paper slowly trying not to allow any solid to get on the filter paper. Then with de-ionized water, rinse your solid in the beaker and let the solid settle then decant the liquid. Repeat the washing twice more and in the last time guide all the solid into the filter paper. Then place the filter paper on a watch glass and then into a warm oven to dry. After it is cool, record the mass of the watch glass, filter paper and solid. If there is not enough time to cool, you may have to do it the next
No vigorous reaction occurred; rather, the zinc sample disintegrated slowly and turned red in color.
Write a balanced chemical equation for each reaction #1-8. Classify each reaction using the information provided in the
-If the copper metal is submerged in the silver nitrate solution then in reaction, a pure, solid (Ag) silver product is created with an excess of (Cu (NO3)2) copper (II) aqueous liquid because a single displacement reaction occurs where the balance equation is then
Before the synthesis of the Copper Iodine Compound, the identities provided (CuNO3)2 and Nal weighed 1.65 g and 4.7 g, respectively. After being weighed, the (CuNO3)2 exhibited a blue color, while the Nal, through observation, was a white color. However, when both identities were combined, the product turned into a brown and red rocky material. Once 20 mL of deionized water was added, the product quickly turned pale pink paste. After the solution was repeatedly washed with a total of an additional 100 mL of deionized water, the product was powdery and pink with small grains, and was left to air-dry. Once the product was air dried, it was observed to be a pale pink color, while the filter paper was stiff as the product was hard and dry. Therefore, the solid was scraped off onto a recrystallizing dish. However, the mass of an empty recrystallizing dish needed to be recorded in order to compare how much of the synthesized copper iodide was obtained. Within this case, the empty recrystallizing dish used weighed 32.01 g, the product on the empty dish weighed 1.03 g, having a total weight of 33.04 g.
I started with elemental copper metal and then reactions occur step by step as follows:
Refer to the reaction of iron nails with a copper solution assignment in Module 3, Section assignment 3.4 Part F of the Chemistry 11 course.
Experimental approach: In the first reaction, copper metal turnings oxidize when put in contact with nitric acid and become copper nitrate.
The lab performed required the use of quantitative and analytical analysis along with limiting reagent analysis. The reaction of Copper (II) Sulfate, CuSO4, mass of 7.0015g with 2.0095g Fe or iron powder produced a solid precipitate of copper while the solution remained the blue color. Through this the appropriate reaction had to be determined out of the two possibilities. Through the use of a vacuum filtration system the mass of Cu was found to be 2.1726g which meant that through limiting reagent analysis Fe was determined to be the limiting reagent and the chemical reaction was determined to be as following:-
Assign one member of the group to gently stir solution with a thermometer (See figure 2)