Question

Iodination product decomposes quickly.why?

Answer 1

I- is a stronger reducing agent in comparison to Cl-Fe+3 is easily reduced by iodide ion.Therefore it gets reduced to iodine.The standard electrode potential of chlorine is much higher,it means it is a better oxiding agent.Also the large size of iodine makes it a strong reducing agent

Hence iodination products are very unstable and decomposes quickly.