How could you tell that a solution was reaching its saturation point?

1 Answer
Oct 15, 2016

Most of the time this would be a quite difficult exercise.


A solution is said to be saturated at a given temperature when the dissolved solute is in equilibrium with undissolved solute, i.e. when the given equilibrium applies:

#"Dissolved solute "rightleftharpoons" Undissolved solute"#

Most of the time, however, the experimenter does not have much handle on the solute that has gone up into solution, and he or she does not know whether the equilibrium has been reached.

The situation is further complicated by the possibility of supersaturated solutions, metastable solutions where the concentration of solute is GREATER than that which would be in equlibrium with undissolved solute.

When you recrystallize something, however, you get a feel for how fast the solute is dissolving: rapid at first, and as saturation point is approached a bit slower. I do realize that I am not really helping you here.