# how would using different salt bridge solutions ( example : sodium chloride Vs. Potassium chloride), affect the voltage of the cell?

cgrant2 | Student

You can figure out this equation by using a standard reduction potential chart and standard potential equation (or Nernst equation).

1. Start off by looking at the reduction of each components of the cell

KCl:  K+ ----- K+ + e- ---> K(s)

NaCl: Na+ ---- Na+ + e-  -------> Na(s)

2. Now determine the anode and the cathode for the voltage cell. This can be determine by looking at a standard reduction potential chart.

K+: -2.71

Na+: -2.931

Since Na+ is higher on the chart and has a larger reduction potential, this is the cathode of the voltage. This means that the K+ is the anode of the cell. The potentials change like so:

K+: -2.71 (anode)

Na+: +2.931 (cathode)

New Equations:

K(s)  ----> K+ e- (-2.71)

Na+ + e- ----> Na(s) (+2.931)

3. Combined both equations and use the standard potential to determine the voltage of the cell.

E(cell) = E(cathode)-E(anode)

K(s) + Na+ ---> Na(s) + K+ = + 5.641

(+2.931)-(-2.71)= +5.641

The voltage increases when NaCl and KCl are added to the voltage cell.