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Do you wanna be rich?
We can help you!
Let's see a video first which teaches you the way to be rich!
Electrorefining
Phyllis ZhangDiana GaoCindy Zhang
Electrorefining is the process of purifying a metal by electrolysis.
+
Slab of impure copper containing such impurities as: Zn, Pb, Ag(Anode)
Pure Cu(Cathode)
- DC power supply
CuSO4(aq)
CuSO4(aq)
Pure Cu(Cathode)
DC power supply
- +
Cu, Zn, Pb, Ag
Examine the following cell
Zn2+
Zn2+
Pb2+
Cu2+
Cu2+
Cu2+
Cu2+
Cu2+
Cu2+ Cu2+
The cathode reaction:
The Cu2+ in solution is preferentially reduced at the cathode but none of the Pb2+ or Zn2+ can be reduced.(Cu2+ exists in larger amounts and has a higher reduction potential than Zn2+ and Pb2+.)
In summary:
No metals above Cu on the table can oxidize and go into solution, and no metal below Cu on the chart can reduce and come back out of solution. As a result, only Cu is involved in both the oxidation and reduction.
Impure anode pure cathode
Exercise----P246
An aqueous solution of SnSO4 was electrolyzed using tin electrodes. The anode contained a few percent of silver, copper and zinc as impurities. Which substances(s) will be oxidized at the anode? Which substances(s) will be reduced at the cathode?
Applications
leadcopper
goldsilverzinc
aluminiumchromium
cobaltmanganese
the rare-earth and alkali metals
Bibliography:the video:http://v.youku.com/v_show/id_XMjk5MDEwMTM2.html
the pictures:http://image.baidu.com
information:http://en.wikipedia.org/wiki/Electrorefining
That's all! Thank you!
Zn
Cu
Ag
Au
Pt
Pb