in a zinc-copper galvanic cell why are the zinc solution and the zinc anode kept separate from the copper solution and copper cathode? a) when combined the copper or zinc solution would react with the opposite electrode b)when combined the two solutions would form a precipitate that would cause the oxidation-reduction reaction to be halted c) when seperated the potential can be measured d) when seperated the electrodes stay pure Solution answer -- C ( when seperated the potential can be meausured ) It is physically impossible to measure the potential difference between a piece of metal and the solution in which it is immersed. We can, however, measure the difference between the potentials of two electrodes that dip into the same solution, or more usefully, are in two different solutions. In the latter case, each electrode-solution pair constitutes an oxidation-reduction half cell, and we are measuring the sum of the two half-cell potentials .