Magnesium Hydroxide Is Used in Several Antacid Formulations $\times$ 10^-12

question 8

Multiple Choice

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 $\times$ 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 these conclusions is justified without additional information.

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