4 AuCl3 (aq) + 12 KOH (aq) → 4 Au (s) + 12 KCl (aq) + 3 O2 (g) + 6 H2O (l)
This is an oxidation-reduction (redox) reaction:
4 AuIII + 12 e- → 4 Au0 (reduction)
6 O-II - 12 e- → 6 O0 (oxidation)
AuCl3 is an oxidizing agent, KOH is a reducing agent.
This is a precipitation reaction: Au is the formed precipitate.
This is a gas evolution reaction, O2 is the formed gas.