How does Changing Salt Bridge Solution affect observed voltages?

[faradayslaw]

Homework Statement

In a lab in which many half-cells are constructed, one of which contains Zn2+, the original salt bridge solution is Potassium nitrate. Suppose we needed to change this solution to Zinc nitrate. What would be the effect on the observed cell potentials?

Homework Equations

Reduction Potential of Zn2+ = +0.76 V
Ecell=Ecathode-Eanode

The Attempt at a Solution

So it seemed at first that the observed voltages would not be altered in all half cells except that with the Zn 2+ ions, since the Zn 2+ ions are not involved in the half-cell reactions, but on the other hand, the high reduction potential of Zn2+ may lead to Zn2+ reducing, rather than the actual metal cations in the anode.

Moreover, for the Zn2+ half cell, the potential difference would increase if the Zn2+ was the anode, and would decrease if Zn2+ was in the cathode.

Please let me know if this is the correct way to think about the problem

Thanks,

 

[Borek]

Salt bridge doesn't change electrode reactions, however, different solution may have different resistance.