Oxidation/reduction reactions involve a change in oxidation number and a transfer of electrons. This was used both in reaction 1 and 5. The first reaction proceeds as : 4 HNO3(aq) + Cu (s) Cu(NO3)2(aq) + 2 H2O (l) + 2 NO2 (g). Precipitation reactions yield a solid product that is insoluble. This occurs in reaction 2 which is: Cu (NO3)2 (aq) + 2 NaOH (aq) Cu(OH)2 (s) + 2 NaNO3 (aq). Decomposition reactions yield a product that is a broken down form of the reactant, such reaction 3 which is: Cu(OH)2 (s) + heat CuO (s) + H2O(l). Acid/base neutralization reactions involve the creation of water and a salt such as the one shown in reaction 4: CuO (s) + H2SO4 …show more content…
It was noticed that the color got into a darker blue as more NaOH was poured in. When stirring, the solution felt like slush and then became more of a liquid as the solution was stirred. In reaction 3, the balanced chemical equation is Cu(OH)2 (s) + heat CuO (s) + H2O(l) When the solution was put on the heater and was brought to a slight boiling point, it was then removed and hot water was added to it. It was observed that this was a decomposition reaction. While adding the hot water to the solution, black dots were appearing. A couple of seconds later the whole solution turned completely black. When 50 mL of hot water was added to the mixture, the black solution separated from H2O going to the bottom of the beaker. After waiting for 5 minutes, another 50 mL of hot water was added and it looked a little more clearer between the solution and the water. It was still clusty and sandy. After waiting for another 5 minutes, another 50 mL of water was added and the separation became more clearer. In reaction 4, the balanced chemical equation …show more content…
However, there was no change of color. Thus, another 0.5 g of Zinc were added and the blue started to fade away from the solution. It started to become more clear. After that, the Zinc changed color from black to red. Then the water was decanted and 10 mL of HCl was added making the solution turn into a yellowish green color. It was used to remove any excess Zinc giving the following balanced chemical equation which is: Zn (s) + 2 HCl (aq) ZnCl2 (aq) + H2 (g). The solution started releasing gas and it lasted about a minute before it stopped producing gas. Then a 5 mL distilled water was