Question

can someone explain this to me, looking at graphs in my textbook, it seems as concentration increases the electric potential goes down? why is this? wouldn't you suspect that as the more concentrated a solution is the greater the electric potential read?

Answer 1

Concentrations that affect electrochemical galvanic potentials are defined in terms of concentrations of ions undergoing oxidation and reduction in their respective cells. That is, when a battery is new, the concentration of ions in solution at the anode (oxidation cell) will be very low and the conc of ions in solution at the cathode will be very high (reduction cell). As the battery discharges, the concentration of ions in the anodic cell increases while the concentration of ions in the cathodic cell decreases. The variation of concentrations is applied to the Nernst Equation to determine the voltage as a function of changing anodic and cathodic cell ion concentrations. E(non-std) = E(std) + RTln([anodic ion conc]/[cathodic ion conc])

Answer 2

thanks mate, i appreciate it