Electrolysis of Potassium Iodide
Procedure:
1. Place a match-head size amount of solid potassium iodide, KI, in the
dish.
2. Add water to half fill the petri dish and stir to dissolve the KI.
3. Add 1 drop of phenolphthalein.
4. Place the tip of the conductivity tester in the solution.
5. Observe the two electrodes for evidence of a reaction.
Questions:
1. What are the possible reactions that can occur at the anode:
Choose the correct reaction and justify your answer.
2. What are the possible reactions that can occur at the cathode:
Choose the correct reaction and justify your answer.
3. Why is iodine produced from potassium iodide and not potassium?
4. Why does the solution become pink in color?
5. Which electrode is the anode and which the cathode?