This is an oxidation-reduction (redox) reaction:
4 Br0 + 4 e- → 4 Br-I (reduction)
2 SbIII - 4 e- → 2 SbV (oxidation)
Br2 is an oxidizing agent, Sb2O3 is a reducing agent.
Reactants:




, Lye 
, KOH
, Lye [Potassium hydroxide] 
; Odorless, white or slightly yellow lumps, rods, flakes, sticks, or pellets. [Note: May be used as an aqueous solution.] 
Products: