If the concentration of [Zn2+] =1.0 x10-3 M and for [Cu2+] = 1.0x10-4 M, compute the potential of the cell using the Nernst Equation.

Answer 1

Zn(s) | Zn²⁺ || Cu²⁺ | Cu(s)

Zn²⁺ + 2e- ==> Zn(s) Eº = -0.76 V

Cu²⁺ + 2e- ==> Cu(s) Eº = 0.34 V

Overall reaction: Cu²⁺ + Zn(s) ==> Cu(s) + Zn²⁺ Eº = 1.1 V (0.34 + 0.76)

Nernst equation:

E_cell = Eº_cell - RT/nF ln Q and assuming standard temperature (a temp wasn't given), this reduces to

E_cell = Eº_cell -0.0592/n logQ

E_cell = 1.1 - (0.0592 / 2) log (1.0x10^-3 / 1.0x10^-4)

E_cell = 1.1 - (0,0296)(1)

E_cell = 1.07 V

(be sure to check the math)