Final answer:
A saturated solution of an ionic compound at equilibrium is depicted by showing both dissolved ions and undissolved solids in a beaker, representing dynamic equilibrium where dissolution and recrystallization rates are equal.
Step-by-step explanation:
A saturated solution of an ionic compound at equilibrium is a balanced system where the rate of dissolution of the solid is equal to the rate of recrystallization. To represent this in a diagram, we would draw a beaker containing a liquid (solvent) with some solid compound (solute) at the bottom; both undissolved solid and dissolved ions of the compound should be present in the solution. For example, sodium chloride (NaCl) at saturation could be represented with solid NaCl crystals at the bottom and Na+ and Cl− ions distributed throughout the aqueous solution above the solid. The following reaction illustrates this equilibrium:
NaCl(s) ⇌ Na+(aq) + Cl−(aq)
This is a dynamic process, indicated by the double arrows (⇌), which means some NaCl is always dissolving into Na+ and Cl− ions while some ions in the solution are crystallizing back to NaCl solid. We call this point where the rates are equal, the solubility equilibrium of the solution. At this point, any added solute will not increase the concentration of dissolved ions, since it will also crystallize at the same rate it dissolves.