State the method used to separate a mixture of NH4Cl and I2.

We have a mixture of ammonium chloride and iodine that we need to separate.  Both compounds are solids.  Ammonium chloride (NH4Cl) is a white solid while iodine (I2) is a dark purple solid.  You could manually separate the particles from one another using a pair of tweezers based on the color difference but that would be tedious and is not what you are looking for.  Both solids are able to sublime (meaning that they can pass directly from the solid phase to the gaseous phase and vice versa) so we cannot separate them that way by heating them.  We must rely on water solubility instead.  Ammonium chloride readily dissolves in water whereas iodine is only sparingly soluble in water.  So we can add water to the mixture to dissolve the ammonium chloride.  We can then filter off the undissolved iodine to isolate it, and boil away the water to remove it and isolate the ammonium chloride again.