If electricity is passed through CuSO4 solution by using Pt electrode then which of the following possible change occurs ?

A. H2 is deposited at cathode
B. Colour of the solution becomes fade (COLOURLESS)
C. Cu is deposited at anode
D. All are possible

¨       The blue colour of copper ions fades due to a decrease in Cu+2 ions and finally, the solution becomes colourless as soon as Cu+2 ions are finished. So, the blue colour of Copper sulphate fades away when electrolyzed using platinum electrodes.

¨       When electricity is passed through the copper sulphate solution, copper sulphate dissociates into copper ions and sulphate ions. The copper ions move towards the electrode connected to the negative terminal of the battery (cathode) and get deposited on it.

¨       Cu is deposited at anode. When electricity is passed through the CuSO4 solution using Pt electrode, Cu2+ ions from the solution move towards the Pt electrode connected to the negative terminal of the battery (cathode) and get reduced to form Cu metal, which gets deposited on the electrode. At the same time, SO42- ions from the solution move towards the Pt electrode connected to the positive terminal of the battery (anode) and get oxidized to form oxygen gas and water.

¨       If copper ions get deposited on the electrode, the concentration of copper ions in the solution decreases. As a result, the intensity of the blue color of the copper sulfate solution decreases. This is because the blue color of copper sulfate is due to the presence of Cu2+ ions in the solution. When the concentration of Cu2+ ions decreases, the blue color of the solution becomes lighter.



Submitted by :- Jamil Ahmed

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