A solution is formed by the mixture of a solute and solvent. A saturated solution is one that contains as much solute in it that it can dissolve at a particular temperature . Any further addition of solute or reduction in temperature of solution will result in a super-saturated solution. This is because the solute will not dissolve when more solute is added and the solute will crystallize out when the temperature is reduced.
An unsaturated solution is one which contains less than the amount of solute it can dissolve at a specified temperature. For example, if a solution of sodium chloride would require 50 g of salt to saturate it, dissolving 40 g of salt will make it an unsaturated solution.
However a colloidal solution is one in which is suspended throughout a liquid. the substance is uniformly dispersed around the liquid.
