Explain the following :
Iodine is more soluble in KI solution than in water.

Explanation

In an aqueous solution of `KI, I_2` form a complex compound `Kl_3`
` KI + I_2 to KI_3`
The compound ionises as follows in water
`KI_3 hArr K^(+) +I_(3)^(-)`
Due to formation of the polyhalide `I_(3)^(-)` ion, `KI_3` dissolves in water. On the other hand, I being non-polar does not dissolve much in water.