Why iodine is more soluble in potassium iodide than in water?
The I2 molecules in iodine are not very soluble in water because they are not opposite in terms of polarity. I2 is non-polar whereas H2O is polar.
But when KI is added to water containing ioidne form a polar compound i.e. KI3, which is composed of K+ and I3- ions.
As the compound become polar or ionic therefore it dissolves in polar solvent i.e. water.