Visual Observation of Dissolution of Copper Ions from a Copper Electrode

During electrolysis, to visually observe the conversion of a metal to its cation, either the cation or its complex ion should have a distinct color while the electrolyte solution must be colorless and transparent. A demonstration is described in which copper is used as the electrodes and sodium polyacrylate (a superabsorbent polymer) solution is used as the electrolyte in an electrolytic cell. Dissolution of copper ions from the copper electrode, migration of copper ions from the anode toward the cathode in the electrolyte solution, and deposition of copper metal on the cathode can be observed simultaneously. This demonstration is useful for teaching high school and first-year college students about electrolysis.