For the cathode of the electrolytic cell I used a coiled piece of Copper wire. For the anode of the cell, I used a small strip of Copper metal a few mm thick. As the electrolyte I used a concentrated solution of Copper Acetate(WSDTY) Acid prepared by diluting glacial acetic acid down to about 50% (roughly estimated) by weight. I used a current controllable (one with a knob which allows be to adjust the current to whatever I wish [within reason] at about 5 volts) power supply. I performed two runs of the cell. One run I used a constant current of about 500 mA for about 30 minutes. The second run I used a current about 300 mA for a few hours, then I lowered it down to 50 or 100 mA overnight. Both runs gave me to the same result. The anode corroded and a dark substance formed on the cathode. The electrolyte solution turned the characteristic blue color as one would expect from a Cu+2 (aq) solution.
While the cathode was immersed in the blue solution, the substance forming on the cathode looked black, but when one lifts the electrode out of solution the substance looked green. Near the bottom of the cathode, the substance looks a little like Copper metal, it has a similar color and shine even though the actual Copper wire is not exposed at that point. The green substance formed on the cathode was not water soluble, nor did it dissolve (or show any signs of a chemical reaction) when it was submerged into concentrated Hydrochloric acid. However, a chemical reaction defiantly occurs when the substance is in the presence of concentrated Nitric acid. The substance reacts with Nitric acid to give off brown NO2 gasses and the solution turns blue as the substance dissolved in the acid. If I had to guess what the substance formed on the cathode was, I would probably say it is Copper metal. However, the color makes me question that slightly. The color (greenish) does not look anything like Copper metal in the usually sense. but maybe that is just because of the way it is plated onto the surface.
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