On passing Cl2 water in a mixture of KBr and KI solution in contact with CCl4 continuously with occasional shaking, we observe

Cl2+2I⊖⟶2Cl-+I2⊖Cl2+2Br⊖⟶Br2+2Cl⊖Oxidising agent: Cl2>Br2>I2Hence, CI2 oxidises I⊝ first to I, which gives violet colour in CCl4,then Br2⊝→Br2,which gives brown colour in CCl4, finally 12 is oxidised to IO⊝. Hence, the CCl4 layer turns colourless.