electroplating..

[sangria1986]

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I swear zumhdal is awful...it has so many mistakes.

Ok, so for en electrolytic cell, the metal that is being reduced in a galvanic cell is now being oxidized correct? And vice versa for the oxidized as well?

How about plating...In the zuhmdal text it says that plating takes place at the anode for electrolytic cell but one of the practice exams indicated that plating takes place at both the cathodes for galvanic and electrolytic cells. which is correct?

Also, if plating always takes place at the cathode, for an electrolytic cell does that mean the new anode (the cathode in a galvanic) is never plating?

Also, in an electrolytic cell, is E (the potential) negative? And delta G for this rxn is positive correct? Hence the need to use an external current...

 

[fizzgig]

just based on the fact that the side of a cell where you're going from aqueous ions to solid metal is the cathode in all the pics i've seen (positive ions go to cathode, meet electrons there, gain electrons, get reduced, red cat...), i'd say plating occurs at the cathode.

if the above is galvanic and you force reversal of the flow of electrons, electrons go to the other side, cations go there, gain e get reduced, red cat. it's the other electrode now but that's the cathode now, and plating is still occuring at the cathode, where ions turn to solid metal.

just my guess.

 

[sangria1986]

just based on the fact that the side of a cell where you're going from aqueous ions to solid metal is the cathode in all the pics i've seen (positive ions go to cathode, meet electrons there, gain electrons, get reduced, red cat...), i'd say plating occurs at the cathode.

if the above is galvanic and you force reversal of the flow of electrons, electrons go to the other side, cations go there, gain e get reduced, red cat. it's the other electrode now but that's the cathode now, and plating is still occuring at the cathode, where ions turn to solid metal.

just my guess.

ok thanks...it makes sense too...since at the anode (oxidation) the metal plate loses electrons and becomes positively charged-since solid metal is uncharged its not being plated there. but at the cathode, the positively charged ions in solution gain electrons and become metal (no charge).