So my textbook states that one of the uses for the Nernst Equation is in calculating the equilibrium constants for reactions that are not redox reactions.

The example that was given was as follows:

Consider a silver concentration cell, in which on the left beaker, there is a 0.1M concentration of AgNO_{3} and in the right beaker, there is a 1M concentration of AgNO_{3}.

Now, if the AgNO_{3} solution in the left beaker is replaced by 1.0M NaCl and an excess of solid AgCl is added to the cell, the nernst equation can be used to calculate the concentration of Ag^{+}, provided that the observed cell potential is given.

What I don't understand, is that since there is no redox reaction, wouldn't the cell potential be 0? (In the succeeding calculations for the Nernst equation, they only used a value of 0 for the standard emf). Also, when they said that an excess of solid AgCl is added "to the cell", is that adding it to both containers? Only the right one?