HW 14.9

[awolff_1D]

I understand how to use the equation to get gibbs free energy, but how do we determine which moles to use when we are given the whole balanced equation? In other words, if we are given E cell for the whole equation, how do we determine the moles to plug into the question?

[Chem_Mod]

You would look at the oxidation states to gauge how many mols of electrons are involved. For part a Ce4+(oxidation number +4)>Ce3+(oxidation number=+3) (so its gaining one electron). Notice how in the complete reaction there are 2 mols of Ce4+ > Ce3+ so you can imagine altogether that for the redox reaction 2 Ce4+ + 2e- > 2Ce3+. Thus, there's a net transfer of 2 electrons and so you would use n=2.

[Evelin Escobedo]

Can someone also go over how to use the equation to get gibbs free energy in this example?

[csebastiani_1B]

Can someone also go over how to use the equation to get gibbs free energy in this example?

n is the moles of e that is transferred and by balancing the reaction in part a we get that n=2 and then F is faradays constant and Ecell is given so you plug in those three to get dG for the reaction