Picture details: (Pic 1 - Background) Picture showing how the electrolysis is done. (Pic 2 - Top Right) The result at cathode and anode. (Pic 3 - Bottom Left) The copper electrode at cathode before and after. (Pic 4 - Bottom Right) The copper electrode at anode before and after. Electrolysis of copper(II) sulphate solution using copper electrodes gives a different result compared to carbon electrodes. Here, I attached a well-combined picture of the experiment and some details on what happened at the anode and cathode.
CATHODE (Electrode that is connected to the negative terminal of battery):
Equation: Cu2+ --> Cu + 2eProduct: Copper
Observation: Copper electrodes become thicker / Brownish metal deposited.
Reason: Copper(II) ions,
Cu2+ are being discharged because of its position is lower than hydrogen ions,
H+ in the electrochemical series. It receives two electrons and converted to copper atom.
ANODE (Electrode that is connected to the positive terminal of battery):
Equation: Cu + 2e --> Cu2+Product: Copper(II) ions
Observation: Copper electrode becomes thinner / Copper electrode dissolves in the solution.
Reason: Copper acts as an active electrode and get involved with the chemical changes. It dissolves in the solution and form copper(II) ions.
I thought my student to use the DEPAN formula for the formation of ions and PODNA for the discharge of ions.
(I think this DEPAN and PODNA are a good action research title...)Pahaikan.com Exclusive: Feel free to use the picture for your chemistry class or you can get the 4 separated file of the combined pictures at RM30.00 without the Pahaikan.com watermark. Contact me at pahaikan@gmail.com.
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