How do i determine the concentration of triiodide ions in solution?

Question

I am reacting potassium iodide and iodine solid. I know I will get some iodide ions and some triiodide ions, so how do i determine the concentrations of each? and is it possible to remove the iodide ions?

Answer 1

Triiodide reacts with starch to give a colored material.  titrate it.

Look up starch-iodide titration.