Comments on: Reduction Potential Question. Calculating delta G http://alkaline-water.info/143/reduction-potential-question-calculating-delta-g/ Learn How To Separate Fact From Fiction Sat, 19 May 2012 13:51:07 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: Chem Man http://alkaline-water.info/143/reduction-potential-question-calculating-delta-g/comment-page-1/#comment-183 Chem Man Sat, 15 May 2010 09:39:13 +0000 http://alkaline-water.info/143/reduction-potential-question-calculating-delta-g/#comment-183 Cu -----> Cu2+ + 2e- Eo = -0.34 V Cr3+ + 3e- ----> Cr Eo = -.073 V 3Cu + 2Cr3+ ----> 3Cu2+ + 2Cr Eocell = -1.07 V This reaction will not occur spontaneously because the Eocell value is negative. dGo = -nFEocell = -6 mol x 96,500 C/mol x (-1.07 J/C) = 620,000 J = 620 kJ dGo is positive, meaning that no useful work can be obtained from this cell. The reason is that it is a nonspontaneous reaction. Cu —–> Cu2+ + 2e- Eo = -0.34 V
Cr3+ + 3e- —-> Cr Eo = -.073 V
3Cu + 2Cr3+ —-> 3Cu2+ + 2Cr Eocell = -1.07 V
This reaction will not occur spontaneously because the Eocell value is negative.

dGo = -nFEocell = -6 mol x 96,500 C/mol x (-1.07 J/C) = 620,000 J = 620 kJ

dGo is positive, meaning that no useful work can be obtained from this cell. The reason is that it is a nonspontaneous reaction.

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