Electrolysis
Electrolysis is a process in which electricity is used to drive a chemical reaction that would not normally happen on its own (a non-spontaneous reaction). It takes place in an electrolytic cell, where an electric current passes through an electrolyte (a substance that conducts electricity when molten or dissolved in water).
How it Works
- An external battery or power source supplies electric current.
- The electrolyte contains positive ions (cations) and negative ions (anions).
- At the cathode (negative electrode) → Cations gain electrons (reduction occurs).
- At the anode (positive electrode) → Anions lose electrons (oxidation occurs).
- As a result, substances are either liberated (like gases) or deposited (like metals) at the electrodes.
Examples
- Electrolysis of water → Produces hydrogen and oxygen gases.
- Electrolysis of molten sodium chloride → Produces sodium metal and chlorine gas.
- Electroplating → Uses electrolysis to coat objects with a thin layer of another metal.