in which type is it neccesary to keep the reactants separate and why??.what are the two key differences between the two cells?
Galvanic cell will have a cell potential that is POSITIVE And Electrolytic cell will have a total cell pot. that is NEGATIVE
It is necessary to keep the reactants separate in both types of cells, otherwise the battery will not work. The key difference between them is that galvanic cells work by themselves, while electrolytic cells need energy to work. Also, galvanic cells have a large k value (1), while electrolytic cells have small k values (1).
It is necessary to keep the reactants separate in a galvanic cell. This is because useful energy is produced only when controlled electron transfer occurs between the two reactants. If they are simply allowed to mix, the electrons are transferred over sub-nanometer distances and the energy is simply given off as heat. Thus, there is no useful energy obtained when a zinc bar is placed into copper(II) sulfate solution, but if the zinc bar is placed in a zinc nitrate solution, the copper bar is placed in a copper(II) nitrate solution, the two solutions are separated by a salt bridge, and a wire connects the two bars, THEN the reaction will be useful. In an electrolytic cell, the products must be kept separate. There is often only one reactant. This is because only the most easily reduced and most easily oxidized species will be discharged by the cell. For example, when electrolyzing a solution of sodium chloride in calcium chloride, the sodium chloride is actually the reactant whereas the calcium chloride is only a flux. The reaction produces sodium and chlorine gases, which would explosively re-combine into sodium chloride if allowed to mix.
