If a more reactive halogen (chlorine for example) is bubbled into the solution of a salt of a less reactive halogen (like bromine) then the more reactive halogen will displace the less reactive one.
Eg. Potassium Bromide + Chlorine --> Potassium Chloride + Bromine
2KBr(aq) + Cl2(g) --> 2KCl(aq) + Br2(aq)
These are redox reactions, with bromide being oxidised and the chlorine being reduced. Note the colour of the reactions by comparing it to the control (chlorine mixed with potassium chlorine).
Eg. Potassium Bromide + Chlorine --> Potassium Chloride + Bromine
2KBr(aq) + Cl2(g) --> 2KCl(aq) + Br2(aq)
These are redox reactions, with bromide being oxidised and the chlorine being reduced. Note the colour of the reactions by comparing it to the control (chlorine mixed with potassium chlorine).