Introduction to Electrochemical Cells
Chemistry: IB Diploma Higher Level, topic 6.7.1
Electrochemical Cells
An electrochemical cell can be used to make an electrical current.
A cell
How is a current made?
- There are two processes happening in a cell: oxidation and reduction.
- One metal is oxidized and gives up electrons.
- In the other side of the cell, the other metal accepts these electrons.
- The electrons travel from one side of the cell to the other via the wire, which is the electrical current.
Electrodes
- Often, you’ll use an electrode that is made of the same metals that are being oxidized or reduced.
- But you don’t have to, and if one of your equations doesn’t involve a solid being formed or lost, you’ll need to use a different metal.
- In these circumstances, we use a platinum electrode because they are inert and so don’t tend to react with anything.
OIL RIG
- OIL RIG is a useful mnemonic for remembering the difference between oxidation and reduction:
- Oxidation Is Loss (of electrons).
- Reduction Is Gain (of electrons).
Test yourself on Introduction to Electrochemical Cells
When an electrode is used that is made from a metal that isn't involved in the redox reaction, what is it usually made from?
When an electrode is used that is made from a metal that isn't involved in the redox reaction, what is it usually made from?