which one of the following is most appropriate to use as an electrolyte for this purpose

Question

If we are performing electrolysis using two iron electrodes, which one of the following is most appropriate to use as an electrolyte for this purpose 

1. Aqueous copper sulphate solution
2. Aqueous iron sulphate solution
3. Aqueous sodium chloride solution
4. All of the above

Answer 1

Aqueous iron sulphate solution since it is soluble and contains the iron that is needed for electrolysis.