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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: greencatshomie on May 20, 2019, 11:43:56 PM

Title: Electrochemistry Question
Post by: greencatshomie on May 20, 2019, 11:43:56 PM
Hello all!

Here’s the problem:

A voltaic cell is formed with one beaker containing a silver wire in a solution of AgNO3 and the other containing a nickel strip in NiCl2. Write the half reactions that occur in each cell.

I’m a little lost as to how I would go about writing these. The answer says

 Ag+ + e- > Ag
Ni > Ni2+ + 2e-

which I understand, however what determines silver as the species being reduced and nickel being oxidized? Why could they not be switched around?

Any help is greatly appreciated! Thanks  :)
Title: Re: Electrochemistry Question
Post by: Borek on May 21, 2019, 03:23:06 AM
Have you heard about activity series? Or have you checked their standard reduction potentials? There are tables with these (experimentally determined) values.
Title: Re: Electrochemistry Question
Post by: greencatshomie on May 21, 2019, 07:56:44 PM
Oh perfect! It makes sense now. Thank you so much