Chemical Forums
Chemistry Forums for Students => High School Chemistry Forum => Topic started by: Wil" on March 25, 2008, 11:32:16 AM
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why can't electrolysis take place with alternate current?
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because your negative ions migrate to the positive electrode and your positives ions migrate to the negative electrode. In AC your positive and negative electrodes are ALTERNATING... therefore your ions will just move to and fro between the two rather than being continuously attracted to any one.
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Dear Wil";
It can take place, if the Frequency is low enough, and the Amplitude high enough.
But also in this case the Anode and the Cathode will change for each Phase their Polarity.
Quintessence: If they change their Polarity fast enough, then the same amount that was just discharged will be charged in the next Phase of the AC on the same Electrode, and so on (The Ions never move away.).
Suma Sumarum: There will be no electrolysis, but the process can be described as a kind of polarisation.
(But a current is “flowing” anyway. It depends on the Definition!)
Good Luck!
ARGOS++
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Be advised, in CVS, cyclic voltage stripping, a reciprocating, but not quite alternating voltage is used, for a variety of purposes, not the least of which to determine plating bath quality. Look it up, it's a pretty fascinating topic, with a variety of other applications, for example, isolated muscle cell physiology.