I did an experiment investigating how a change in the concentration of zinc sulphate in electrolysis affect the zinc collected at the cathode. I used zinc electrodes for the experiment and did it with 0.1,0.2,0.3,0.4,0.5,0.6, 1.0M. I expected the lower concentration, the less products formed. But instead the lower the concentration the higher the amount of zinc produced.
Concentration/M Initial mass / g Final mass / g Change / g Current / A Percentage error
0.10 0.911 0.986 0.075 0.14 778%
0.20 0.937 1.053 0.116 0.29 555%
0.30 0.928 1.008 0.080 0.33 297%
0.40 0.933 1.029 0.096 0.65 142%
0.50 0.968 0.983 0.114 0.74 152%
0.60 0.893 0.966 0.073 0.63 90%
1.00 1.18 1.229 0.049 0.93 -13%
Would this be because of overpotential or simply high errors and would this have anything to do with the Nernst equation? I saw that cell potential depends on concentration. If we reduce the concentration of the solution, it reduced the equilibrium value and makes the equation more spontaneous and hence more products formed ideally. Does this mean that in electrolysis of zinc sulphate using zinc electrodes if I decrease the concentration of zinc sulphate from 1.0M to 0.5M, I will get more zinc produced at the cathode? This confuses me because I thought that the lower the concentration, the less ions in solution and so less product produced. Thanks!!