Specification description - 5.4.3.4 Electrolysis of aqueous solutions
The ions discharged when an aqueous solution is electrolytes
using inert electrodes depend on the relative reactivity of the
elements involved.
At the negative electrode (cathode), hydrogen is produced if the
metal is more reactive than hydrogen.
At the positive electrode (anode), oxygen is produced unless the
solution contains halide ions when the halogen is produced.
This happens because in the aqueous solution water molecules
break down producing hydrogen ions and hydroxide ions that are
discharged.
Students should be able to predict the products of the electrolysis of
aqueous solutions containing a single ionic compound.
