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Photosynthesis Lab Report

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Results:
Mass of copper wire: 0.28g
Mass of empty beaker: 68.49g
Mass of beaker and dry copper: 68.84g
Mass of recovered copper: 0.35g
Percent copper recovered: 0.35g / 0.28g * 100% = 125%
Observations:
When the 2.0 mL of concentrated nitric acid is poured onto the copper wire, the solutions turns green at first, with a lot of rust-coloured gas coming out the top. The solution slowly turns blue as the copper dissolves, and less gas is emitted. When the reaction is complete, Cu(NO₃)₂ is left in the solution.
When Cu(OH)₂ is added to the solution, the solution turns a darker blue and appears to have particles in it. Besides Cu(OH)₂, NaNO₃ has also formed in the solution. While heating the solution on the hot plate, the solution begins to turn darker in colour and gradually turns black. There appears to be solid particles in the solution. During the washing and decantation process, any excess NaNO₃ is removed from the solid CuO.
The …show more content…

This resulted from the copper not being completely dry before the final weighing. The copper clung to the porcelain dish when being transferred to the beaker to weigh, which most likely means there was still some remaining water and/or methanol on the copper that did not evaporate, resulting in an impossible recovery percentage. If this mistake had not been made, the full amount of copper would most likely not have been recovered. When washing, decanting, and transferring the copper from one container to another, it is next to impossible to recover all of the copper, especially when given time constraints. There is very little that can be done to prevent this other than careful transfers and

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