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Topic: Electrochemistry question  (Read 3294 times)

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Offline spirochete

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Electrochemistry question
« on: February 07, 2009, 03:07:14 PM »
When looking at a potential for a half reaction, is it appropriate to say that the reaction is favorable or not favorable?  Or do you have to combine it was another half reaction to make that determination?

For example CuI+e -->Cu+ I- has a reduction potential of -0.19 volts at standard conditions.

Would it be correct to say that this reaction is not favorable?  Or at least less favorable than another half reaction with a more positive potential?

Offline FeLiXe

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Re: Electrochemistry question
« Reply #1 on: February 08, 2009, 03:22:29 PM »
implicitely you always have hydrogen on the other side if you talk about a half reaction
the minus says that

CuI + 1/2 H2 -> Cu + HI

is not favorable
but you don't have isolated half reactions

another way of saying it of course is that your system
CuI+e -->Cu+ I- is a rather strong reducing agent (if you start out with Cu + I-)
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