[esterbunny]

Hey guys  ,
I am trying to apply the nernst equation into an assignment but am having trouble doing so ..

I have recently been doing an experiment involving an electrochemical cell - two aq solutions (CuSO₄ and MgSO₄), with an anode and cathode, connected by a salt bridge and wire.

I am attempting to find the effect that changing the concentrations of solutions has on the voltage / current produced, and then secondly the effect that changing the temperature of the solutions has on the voltage / current produced.

This is what i have so far, which is probably wrong

Mg | Mg ²⁺ || Cu ²⁺ | Cu

and the reaction is:

Mg + Cu ²⁺ = Mg ²⁺ + Cu


Therefore both having 1M concentrations:

E = E(0) - (RT/nF)ln([oxidized]/[reduced])

E = E(0) - (.0591/n)log([oxidized]/[reduced])

E = E(0) - (.0591/2)log([Mg]/[Cu])

E = E(0) - 0.02955 x log (1/1)

E = E(0) - 0.02955 x 0

Where E(0) = -2.72V


-- So this is where I get a little lost ... --

Have I used this equation correctly?

Does this equation show that concentration and temperature have no effect of the voltage potential of a cell?

In my results I have found that an increase in temperature increases the current (I) in the cell. If the above is true, that voltage is constant, have I then decreased the resistance within the cell (According to V = I R)?

Or have I got this all wrong ..

Any help would be greatly appreciated 

Cheers