Copper Cycle Lab Report
Copper Cycle Summary
During the copper cycle lab, my partners and I performed a series of reactions on copper powder and observed the changes it underwent. For the first step, we mixed nitric acid and copper powder, and noticed that a yellowish brown gas emerged, along with effervescence. The red solid disappeared and became a blue liquid. We know that we produced copper nitrate, nitrate gas, and water because the only two blue solutions in “A New Language” are copper sulfate and copper nitrate. It would make sense for us to have created copper nitrate, since we mixed copper with nitric acid, not sulfuric acid. The nitrate that we created was the brownish gas that we watched float up during the reaction. In addition, the water came from
the hydrogen and oxygen molecules that split off. Cu(s) + HNO3(aq)Cu(NO3)2(aq) + NO2(g) + H2O(l).
Next, we added sodium hydroxide to the copper nitrate, and we observed that clumps of a dark blue gel-like solid were formed, with a colorless liquid on the top. We are sure that we produced copper hydroxide and sodium nitrate because copper hydroxide in solid form is blue-green crystals (which would be the gel-like solid we witnessed), and sodium nitrate is the colorless liquid we saw. Besides, it makes sense that the sodium and the hydroxide split apart, as did the copper and the nitrate, to mingle with one another and create new molecules. Cu(NO3)2(aq) + NaOH(aq)Cu(OH)2(s) + NaNO3(aq).
In the third step of the lab, we heated the copper hydroxide, and we noted that the blue clumps turned into a brown/black solid. Since copper oxide is the only black powder in “A New Language”, we know that we produced copper oxide as well as water, since the hydrogen and half of the oxygen molecules had to have split off. Cu(OH)2(s)CuO(s) + H2O(l).
Then we incorporated sulfuric acid in the copper oxide, and we observed that the black solid disappeared and the solution turned blue. We realize that we created copper sulfate and water because once again, we got a bright blue solution, but this time we know that it is copper sulfate instead of copper nitrate, because we added sulfuric acid to the mix. The hydrogen molecules also couldn’t have just disappeared, so they formed water. H2SO4(aq) + CuO(s)CuSO4(aq) + H2O(l).
Finally, we added zinc to the copper sulfate, and we witnessed that the solution became cloudy while it was fizzing, and a clear liquid with a brick red solid in it emerged. We know that we produced copper powder and zinc sulfate because copper is the red powder that we saw at the beginning of the lab, and zinc sulfate is a clear solution. We can also think of this reaction as the sulfate leaving the copper and joining the zinc. Zn(s) + CuSO4(aq)Cu(s) + ZnSO4(aq).
This lab is called the copper cycle because it is composed of a series of reactions that cause the copper to change phases of matter and mix with other chemicals, until eventually returning to its original self in solid form. Throughout the lab, the copper goes from being a red solid, to being in a blue liquid, in blue clumps, in a brown/black solid, in a blue liquid, and finally becoming a red solid once more.
During the copper cycle lab, my partners and I performed a series of reactions on copper powder and observed the changes it underwent. For the first step, we mixed nitric acid and copper powder, and noticed that a yellowish brown gas emerged, along with effervescence. The red solid disappeared and became a blue liquid. We know that we produced copper nitrate, nitrate gas, and water because the only two blue solutions in “A New Language” are copper sulfate and copper nitrate. It would make sense for us to have created copper nitrate, since we mixed copper with nitric acid, not sulfuric acid. The nitrate that we created was the brownish gas that we watched float up during the reaction. In addition, the water came from
the hydrogen and oxygen molecules that split off. Cu(s) + HNO3(aq)Cu(NO3)2(aq) + NO2(g) + H2O(l).
Next, we added sodium hydroxide to the copper nitrate, and we observed that clumps of a dark blue gel-like solid were formed, with a colorless liquid on the top. We are sure that we produced copper hydroxide and sodium nitrate because copper hydroxide in solid form is blue-green crystals (which would be the gel-like solid we witnessed), and sodium nitrate is the colorless liquid we saw. Besides, it makes sense that the sodium and the hydroxide split apart, as did the copper and the nitrate, to mingle with one another and create new molecules. Cu(NO3)2(aq) + NaOH(aq)Cu(OH)2(s) + NaNO3(aq).
In the third step of the lab, we heated the copper hydroxide, and we noted that the blue clumps turned into a brown/black solid. Since copper oxide is the only black powder in “A New Language”, we know that we produced copper oxide as well as water, since the hydrogen and half of the oxygen molecules had to have split off. Cu(OH)2(s)CuO(s) + H2O(l).
Then we incorporated sulfuric acid in the copper oxide, and we observed that the black solid disappeared and the solution turned blue. We realize that we created copper sulfate and water because once again, we got a bright blue solution, but this time we know that it is copper sulfate instead of copper nitrate, because we added sulfuric acid to the mix. The hydrogen molecules also couldn’t have just disappeared, so they formed water. H2SO4(aq) + CuO(s)CuSO4(aq) + H2O(l).
Finally, we added zinc to the copper sulfate, and we witnessed that the solution became cloudy while it was fizzing, and a clear liquid with a brick red solid in it emerged. We know that we produced copper powder and zinc sulfate because copper is the red powder that we saw at the beginning of the lab, and zinc sulfate is a clear solution. We can also think of this reaction as the sulfate leaving the copper and joining the zinc. Zn(s) + CuSO4(aq)Cu(s) + ZnSO4(aq).
This lab is called the copper cycle because it is composed of a series of reactions that cause the copper to change phases of matter and mix with other chemicals, until eventually returning to its original self in solid form. Throughout the lab, the copper goes from being a red solid, to being in a blue liquid, in blue clumps, in a brown/black solid, in a blue liquid, and finally becoming a red solid once more.