Salt bridge. A salt bridge consists of a saturated solution of NH4NO3 or KCl mixed with gelatin or agar jelly filled in a glass tube bent according to the requirement of the experiment.
(i) Salt bridge prevents mixing of two electrolytes.
(ii) Prevents junction potential.
(iii) Maintains electrical neutraility.
= 1.05 V – 0.0295 x log 80
= 1.05 V – 0.0295 x 1.9031
= 1.05 V – 0.056 = 0.99 V.