At 25 degrees Celsius, the solubility product (Ksp) and the solubility (s) of magnesium hydroxide (Mg(OH)₂) are crucial for understanding its behavior in solution. The solubility of magnesium hydroxide is notably low, meaning it does not dissolve well in water. When Mg(OH)₂ dissolves, it dissociates into magnesium ions (Mg2+) and hydroxide ions (OH–).
The Ksp expression for magnesium hydroxide is:
Ksp = [Mg2+][OH–]2
From this, we can see how its solubility affects the concentration of ions in the solution. If ‘s’ is the solubility of Mg(OH)₂, then at equilibrium, we have:
[Mg2+] = s
[OH–] = 2s
Substituting these values into the Ksp expression gives:
Ksp = (s)(2s)2 = 4s3
This shows a key relationship: the solubility product Ksp is directly related to the solubility ‘s’ of magnesium hydroxide. A higher Ksp indicates a higher solubility of Mg(OH)₂. Moreover, the pH of the solution can be calculated, given that the concentration of hydroxide ions influences pH significantly.
Therefore, for magnesium hydroxide, the correct interpretation at 25 degrees Celsius is that its solubility product provides insights into its solubility and the resulting pH of the solution.