Question

What are the products of the electrolysis of 0.5mol/L potassium iodide solution with carbon electrodes?

Answer 1

The products of the electrolysis of a 0.5mol/L potassium iodide (KI) solution with carbon electrodes are potassium (K) and iodine (I2).

At the anode (positive electrode), oxidation occurs. Carbon electrode reacts with hydroxide ions (OH-) from water to form carbon dioxide gas (CO2) and water (H2O).
2OH- → 2e- + 1/2O2 + H2O

At the cathode (negative electrode), reduction occurs. Iodide ions (I-) are oxidized to iodine (I2) by gaining electrons.
2I- → I2 + 2e-

Overall, the net equation for the electrolysis of potassium iodide solution is:
2KI + 2H2O → 2KOH + H2 + I2