The Solubility of Solids in Liquid is expressed in two ways.

The maximum amount in grams of a solid that can be dissolved in 100g of a solvent at a certain temperature is called the Solubility of that substance.

Therefore, the unit of Solubility is = gm per 100gm of solvent.

This unit is often used in experimental work.

In theoretical or computational work, Solubility is expressed as moles per liter.

Therefore, the maximum number of moles of a solid that can be dissolved in one liter of solution at a given temperature is called the solubility of that substance.

So the unit of solubility is mol/Litre.

That solution in which maximum amount of substance is dissolved is called Saturated Solution.

At The Same Temperature No more solute can be added to a Saturated Solution.