- There are two approaches for performing this experiment - on a filter paper and in a U-tube. Consider only the option on a paper.
- Prepare the solution of [Cu(NH3)4]CrO4. Pour half a spatula of copper sulfate pentahydrate into a test tube. Then, add 2 ml of aqueous ammonia. Stir the mixture to complete dissolution of the copper sulfate. Add about a quarter of a spatula of potassium chromate and stir the resulting mixture.
- Carefully apply the resulting solution to form a line across the filter paper.
- Dry the filter paper. You can repeat steps 3 and 4 several times, applying the solution to the same line. Thus, the experiment will be more spectacular.
- Moisten the filter paper with the solution of sodium sulfate.
- Fill two Petri dishes with sodium sulfate and drop the ends of the filter paper into them.
- Lower electrodes into the Petri dishes. Pass electricity for at least 15 minutes.
- Observe the migration of ions.