What is the name of the reaction of chlorine and potassium iodide?

Chlorine is bubbled through the potassium iodide layer. The chlorine reacts with the iodide to form iodine. In the aqueous layer the brown triiodide ion is formed by the reaction of iodine with iodide. In the carbon tetrachloride layer, iodine forms a purple solution.

Potassium react with chlorine to produce potassium iodide and iodine