What would happen if more solute is added to a solution after the saturation point reached?

Question

Naomi Aronson · Accepted Answer

There would be #"undissolved solute"# visible in the solution.

#"Saturation"# defines an equilibrium property: that the concentration of the solute in solution is the same as the concentration there would be in the presence of UNDISSOLVED solute. And thus for an ionic solute, #MX#, in water we could write: #MX(s) rightleftharpoonsM^(+) +X^(-)# As for any equilibrium we could quantify this by measuring an equilibrium constant, #K_"sp"# #=# #[M^+][X^-]#, which is quoted for a specific temperature. The #"sp"# stands for #"solubility product"#, and it is measured for a variety of sparingly soluble and insoluble salts. Why? Well, suppose you were isolating precious metal salts, such as those of gold or platinum or iridium; you don't want to throw these salts down the sink. Likewise, if you had salts of lead or mercury or cadmium, you don't want to throw these salts away, for the reason that you might poison the waterways. So if more solute were added to a solution at equilibrium, likely more precipitate would collect at the bottom of the flask.

Natalie Anton · Answer

undefined Adding more solute to a saturated solution will not result in further dissolution. Instead, the excess solute will remain undissolved at the bottom of the container. This is because the solution has already reached its maximum solubility, and any additional solute cannot be accommodated by the solvent.