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Which element is primarily used as the cathode in the electrolytic refining of copper?
Impure copper
Pure copper
Zinc
Iron
Pure copper
In the electrolytic refining of copper, a thin strip of pure copper is used as the cathode, while a thick block of impure copper serves as the anode. When current is passed, pure copper is deposited onto the cathode from the copper sulfate solution.
In the electrolytic refining of copper, a thin strip of pure copper is used as the cathode, while a thick block of impure copper serves as the anode. When current is passed, pure copper is deposited onto the cathode from the copper sulfate solution.
Think of it like a laundry machine: the impure anode is dirty clothes, the electrolyte solution is water/detergent, and the pure cathode is the final clean garment where the 'cleaned' copper accumulates.
Remember 'PANIC': Positive Anode, Negative Is Cathode.
Cu2++2eтИТтЖТCu(s) тАФ Reduction at the cathode
Cu(s)тЖТCu2++2eтИТ тАФ Oxidation at the anode
During electrolysis, copper atoms from the impure anode lose electrons to form Cu2+ ions which enter the electrolyte solution. Simultaneously, Cu2+ ions from the solution gain electrons at the cathode to form pure metallic copper. The process is represented by the reactions: Anode: Cu(s)тЖТCu2+(aq)+2eтИТ; Cathode: Cu2+(aq)+2eтИТтЖТCu(s).
The electrolyte used is acidified copper sulfate (CuSO4тАЛ solution).
Impure metals like silver and gold settle at the bottom of the anode as 'anode mud'.
The purity of copper obtained through this process is typically 99.99%.
Produces highly pure copper suitable for electrical applications.
Allows for the recovery of precious metals like gold and silver from anode mud.
Requires significant electrical energy consumption.
The process is relatively slow and requires large industrial setup.
Manufacturing of electrical wires and cables.
Electroplating industry for decorative and protective coatings.
| Feature | Anode | Cathode |
|---|---|---|
Electrode Type | Impure Copper | Pure Copper |
The electrolyte is generally a solution of copper sulfate mixed with dilute sulfuric acid.
Option A is the anode, while Zinc and Iron are impurities often found in the blister copper ore.
B is correct тАФ A thin strip of pure copper is used as the cathode to collect the refined metal during electrolysis.
Always remember that in any electrolytic cell, the cathode is the site of reduction, and the anode is the site of oxidation. This rule applies universally across chemistry.