- Redox reactions involve the transfer of elections
- Electricity is simply the flow of electrons
- Hence, having the reduction and oxidation reactions in two locations, with a wire to connect them and a salt bridge used to complete the circuit, a cell can be created
- The flow of electrons in the wire creates electricity and can be used to power light bulbs etc.
- Note whilst electron flow goes from the negative terminal to the positive terminal, conventional current flows the opposite way.
Also called: voltaic cell; Galvanic cell
- A device that makes a normal chemical reaction occur in such a way that it generates electricity.
- Electrodes: conductors of a cell which get connected to the external circuit
- Reactions occurring at electrodes are called electrode process/reactions
- The salt bridge allows ions to migrate and completes the circuit
- One electrode (the anode) liberates electrons through oxidation which flows up the conductor
- These electrons flow through the conductor to the other electrode (cathode)
- The reaction at the cathode, reduction, consumes these electrons
- Ions migrate through salt bridge to maintain electrical neutrality
An oil rig cat:
Oxidation occurs at the anode
Reduction occurs at the cathode
2 H+ + Zn + 2MnO2 –> Mn2O3 + Zn2+ + H2O