[DUDE778]

Cu2+(aq) + 2e−  -> Cu(s)   E° = 0.339 V

O2(g) + 2H+(aq) + 2e−  -> H2O(l)   E° = 1.2291 V

S2O82−(aq) + 2e−  -> 2SO42−(aq)   E° = 2.01 V

1. The amount of copper in a Cu2+/H2SO4 solution is to be determined by electrogravimetry. If the cuprate concentration is initially [Cu2+] = 0.001000 M, what would be the ideal cathodic potential versus SHE when 99.0% of the possible copper metal has been deposited?

2. Ideally, what voltage must be applied to a platinum-electrode electrolytic cell containing this solution at pH=1.01 in order to obtain this degree of deposition?
(For this excercise, ignore any possible contribution from anode over-potential, or potential drop due to solution polarization or cell resistance.)


Can someone get me started on these two questions

THank you

[Rabn]

Nernst and delta G are your saviours when dealing with these types of equations. Start with the nernst equation.

[DUDE778]

i dont know if it got it right.
Cu2+ + 2e- -> Cu   E=0.339
E=0.339-0.05916/2log(1/0.001)
E=0.25026

Is this right?
i am not sure what 99% of the copper metal is deposited means...

[Rabn]

What that means is that 1% of the copper is left in solution as Cu²⁺. That would mean that if you had 1 liter of this solution there would be 1.00 x 10^-5 moles of Cu²⁺ in the solution and you would then use that amount of ion to calculate the potential.