G A solution contains both Mg2 (aq) and Fe3 (aq) ions. The concentration of each of these ions in the solution is 0.01 M. The hydroxides of these ions, Mg(OH)2 and Fe(OH)3, respectively, have very different solubilities. What condition will lead to precipitation of one ion but not the other

The correct answer is "Set the pH to acidic conditions (pH 3) and Fe(OH)3 will precipitate but not Mg(OH)2".

Explanation:

The value of equilibrium constant (Ksp) determines the degree at which a component solubilizes in water. The higher the Ksp, the more easily a substance is solubilized in water. In this case, the Ksp is determined by the concentration of hydroxides and Mg(OH)2 has a much higher Ksp value than Fe(OH)3. Therefore, the best way to precipitate one ion but not the other will be to put the ions at a low hydroxide concentration, such at an acidic pH. In this condition Fe(OH)3 will precipitate but not Mg(OH)2, because the latter is much more soluble and will be soluble even at a low hydroxide concentration. I attached the missing Ksp values and the missing options for this question.