I'm trying to find the electrochemical equivalent for zinc in an experiment. I am carrying out electrolysis of zinc sulfate solution. According to Faraday's law, m=zq. I made a 0.1 M solution and kept time for electrolysis constant (1 min). To get a value for z I plotted the mass over the charge (I*t). The current was varied. I'm getting a linear trend (mass deposited increases with increase in current) but a huge discrepancy of 100%. Also in the experiment, after the electrolysis I noticed that the zinc separated and got suspended in the solution when I disconnected the electrode to measure the new mass. This could have affected results. Any reasons for this? I might be able to redo the experiment if someone knows how I can solve this or get better results. The metal ions should undergo reduction at the cathode. Maybe that's not happening?
P.s I also did it for copper sulfate and it was worse. Almost no copper stayed on the electrode after electrolysis Also I used graphite electrodes for this. Before this, for another experiment I electroplated zinc with copper and all of it deposited. Maybe get better results with zinc/copper electrodes for this experiment instead of graphite?