Electrolysis - Process
Chemistry: Edexcel IGCSE, topic 7.1.2
Electrolysis
Electrolysis is the process that splits ionic compounds into the different elements that they are made of. Electrolysis happens using a solution that conducts electricity.
Electrolyte
- When ionic compounds are melted or dissolved in water, the ions (charged particles that have gained/lost electrons) are free to move around, and the liquid/solution will conduct electricity.
- Ionic compounds that dissolve in water to make a solution that conducts electricity are called electrolytes.
Electrodes
- When a voltage (direct current) is applied across an electrolyte, the charged ions are attracted to the electrode with the opposite charge to the ion.
- Positively charged ions are attracted to the negative electrode (cathode).
- Negatively charged ions are attracted to the positive electrode (anode).
Elements
- When an ion touches an electrode, electrons can be transferred, producing elements.
- E.g. if copper ions (Cu2+) are in a solution and a voltage is applied, they'll move to the cathode (negative electrode). When they touch the cathode, each Cu2+ ion will gain 2 electrons and form a copper metal.
Test yourself on Electrolysis - Process
If copper ions (Cu2+) are in a solution and a voltage is applied, which electrode will they move towards and what will happen when they touch that electrode?
What happens when ionic compounds are dissolved in water?