Magnesium Hydroxide Is Used in Several Antacid Formulations

Magnesium hydroxide is used in several antacid formulations. When it is added to water it dissociates into magnesium and hydroxide ions. Mg(OH) ₂(s) Mg²⁺(aq) + 2OH^-(aq)
The equilibrium constant at 25°C is 8.9 × 10^-12. One hundred grams of magnesium hydroxide is added to 1.00 L of water and equilibrium is established. What happens to the solution if another 10 grams of Mg(OH) ₂ are now added to the mixture?

A) The hydroxide ion concentration will decrease.
B) The hydroxide ion concentration will increase.
C) The hydroxide ion concentration will be unchanged.
D) The solution will become supersaturated.
E) None of the above conclusions is justified without additional information.