The membrane keeps the chlorine gas awayfrom the sodium hydroxide solution.

It allows ions through but not molecules

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

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

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 present: Na+, Cl- from sodium chloride H+ , OH- from water

Ions remaining: Na+ (aq) OH- (aq)

Ions present: Na+, Cl- from sodium chloride H+ , OH- from water

Ions remaining: Na+ (aq) OH- (aq)

c hs h s

c h

NaOH + H2 + Cl222 2

Sodium metal at cathode

Chlorine gas at anode