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

1 Answer | Add Yours

cgrant2's profile pic

cgrant2 | High School Teacher | (Level 1) Valedictorian

Posted on

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. 



We’ve answered 317,405 questions. We can answer yours, too.

Ask a question