How to use Nernst equation?

Question

Using the Nernst equation calculate the cell voltage for

Fe(s) + Cd2+(aq) ---> Fe2+(aq) + Cd(s)

when the [Fe2+] = 0.16 M and [Cd2+] = 1.6 M.

thanks

Answer 1

For aA+bB -> cC+dD

E=E0-(RT/nF)* ln([C]^c*[D]^d / ([A]^a*[B]^b))

where n=number of electrons taking part in the reaction

Solids are not considered in the equation, so in your case

E=E0 -(RT/nF)*ln([Fe2+]/[Cd+2])

You can find the standard reduction potentials for the Fe+2 and Cd+2 at
http://www.northland.cc.mn.us/Chemistry/standard_reduction_potentials.htm
Then E0= E0(Cd2+)-E0(Fe2+)
R=8.314
n=2
F=96500

You have to specify T ...

Answer 2

that's used in biology to calculate the resting potential of a molecule interior a cellular. Eg. potassium has a resting potential interior a cellular of -90mV, mutually as sodium has a resting potential of +60mV.