How can you compere the relative solubilities of different slats in the same solvet ?

Which of the following methods can be used to seperate two compounds with different solubilities in the same solvent?

How will you separate a mixture of two solid compounds of different solubilities in the same solvent?

How will you separate a mixture of two solids which differ in their solubilities in the same solvent ?

How will you justify that ice, water and steam are not different substances but different states of the same substance ?