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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: offlinedoctor on September 05, 2012, 04:23:41 AM

Title: Electroplating Preferential Reactions
Post by: offlinedoctor on September 05, 2012, 04:23:41 AM

Hi,

I'm just wondering for Eletroplating, why do we assume that for something such as Copper, if we use that to coat an item, it would be oxidised at the anode, and also reduced at the Cathode (to form the coating), why isn't water reacted at all in these instances?

Title: Re: Electroplating Preferential Reactions
Post by: 123456789 on September 05, 2012, 05:07:27 AM

For copper, at the anode, oxidation takes place. Since the electrode is not inert, the electrode will react. So copper is oxidised. Then at the cathode, it is reduction, so copper is reduced. There is nothing to do with H+: Hydrogen is more reactive than copper so copper will be preferentially discharged anyway.

However, if the metal is more reactive than Hydrogen, (for example iron (II), then yes hydrogen will be liberated, if I'm not wrong.