Please help me with this chemistry question?!Watch this thread
Aqueous chlorine is shaken with aqueous potassium bromide in the presence of an organic solvent such as 1,1,1-trichloroethane. 
Chlorine is more reactive than bromine, so it will oxidise the bromide ions to form elemental bromine. At the same time, the chlorine will be reduced to form chloride ions.
Cl2 + 2Br- ====== Br2 + 2Cl-
A non-polar solvent is chosen so that it forms a separate layer. I would normally use cyclohexane which is less dense than water and will float on top. 1,1,1-trichloroethane is more dense than water so it will form the lower layer. The non-polar solvent will dissolve the elemental halogen, in this case bromine so it will take on an orange colour, indicating that the redox/displacement reaction has taken place.
If you mixed the chlorine with an iodide solution instead then iodine would be liberated. What colour would be formed in the organic layer in this case?
Hope this helps!