Key Stage 4
Meaning
A half equation is a type of symbol equation which shows how individual ions gain or lose electrons at an electrode during electrolysis.
About Half Equations
- In half equations only one ion is considered at a time, or the changes at one electrode.
- Half equations use the letter 'e' to represent electrons.
- Half equations can be taken from balanced symbol equations.
Examples
Balanced Symbol Equation: 4Li + O2 → 2Li2O
Half Equation at cathode: Li+ + e- → Li
Half Equation at anode: 2O-2 → O2 + 4e-