1. Electrolytic Cells Section 9.2

2. Vocabulary Electrolysis: electrical energy used to bring about a non-spontaneous redox reaction Electrolyte: any substance containing free ions that make the substance electrically conductive; typically an ionic solution or molten ionic compound

3. Electrolytic Cell Electrodes are placed in an electrolyte A wire connects the electrodes and electricity is supplied This causes a non-spontaneous reaction to “go” Anode: positive charge, attracts anions, oxidation occurs Cathode: negative charge, attracts cations, reduction occurs

4. Generic Electrolytic cell

5. More Electrifying Stuff Electrolytic cells convert electrical energy to chemical energy Electron flow is from the anode to the cathode Applied emf must be greater than the emf for the cell

6. Electrolysis of Molten Sodium Chloride Cl - ions are attracted to the anode and lose electrons Chlorine gas is formed 2Cl - → Cl 2 + 2e- Na + ions are attracted to the cathode and gain electrons Sodium metal is formed Na + + e - → Na

7. Uses for Electrolysis Obtain reactive metals from their ores Produce elemental gases (Br 2, Cl 2, etc.) Recharge rechargeable batteries Plating one metal onto another metal (electroplating)