Which of these changes will produce the most positive voltage for this half reaction in the direction written?

Question

CO^+2 (aq) + 2e- --> Co(s) Standard E = -0.28 V

a) increasing the amount of solid Co

b) decreasing the amount of solid Co

c) increasing the concentration of CO^+2

d) decreasing the concentration of CO^+2

I need detailed explannation as well

Answer 1

Eo = (RT/nF)lnK

Remember that removing or adding solid in an equilibrium system doesn't affect equilibrium constant, K.  Thus, you are left with C or D.

Now think about it.  Do you think reducing the [ ] of Co2+ ions will help increase or decrease the overall voltage of the half-reaction?  Work from that.

[Answer: see above]