The membrane keeps the chlorine gas away from the sodium hydroxide solution. It allows ions through but not molecules

i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 During electrolysis; i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 Chloride ions form Chlorine molecules by depositing electrons at the positive anode ii) at the negative terminal: Reduction is electron gain 2H+ + 2e- H2 hydrogen ions form hydrogen molecules by receiving electrons from the negative cathode A reaction where both reduction and oxidation occurs is called a ‘Redox’ reaction. ( OIL RIG ! ) CO2 + C CO

i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 During electrolysis; i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 Chloride ions form Chlorine molecules by depositing electrons at the positive anode ii) at the negative terminal: Reduction is electron gain 2H+ + 2e- H2 hydrogen ions form hydrogen molecules by receiving electrons from the negative cathode A reaction where both reduction and oxidation occurs is called a ‘Redox’ reaction. ( OIL RIG ! ) CO2 + C CO

i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 During electrolysis; i) at the positive terminal: Oxidation is electron loss 2Cl- - 2e- Cl2 Chloride ions form Chlorine molecules by depositing electrons at the positive anode ii) at the negative terminal: Reduction is electron gain 2H+ + 2e- H2 hydrogen ions form hydrogen molecules by receiving electrons from the negative cathode A reaction where both reduction and oxidation occurs is called a ‘Redox’ reaction. ( OIL RIG ! ) CO2 + C CO

Ions remaining: Na+ (aq) OH- (aq) Ions present: Na+, Cl- from sodium chloride H+ , OH- from water Ions remaining: Na+ (aq) OH- (aq)

Ions remaining: Na+ (aq) OH- (aq) Ions present: Na+, Cl- from sodium chloride H+ , OH- from water Ions remaining: Na+ (aq) OH- (aq)

c h s h s c h 2 2 2 NaOH + H2 + Cl2 Sodium metal at cathode Chlorine gas at anode