Chemistry - molar solubility?
Here is the question: Calculate and compare the molar solubility of Mg(OH)2 in water and in a solution buffered at a pH of 5.5. Determine the molar solubility of Mg(OH)2 in water and the pH of a saturated Mg(OH)2 solution.
- davidLv 72 months agoFavorite Answer
You need Ksp for Mg(OH)2 ... wait a sec, while i go to google == If you had looked it up in your book and posted it, then it would not take as long.
Mg(OH)2 <--> Mg(2+) + 2OH(-)
Ksp = 1.5x10^-11 = [Mg(2+)][OH(-)]^2 = x(2x)^2 = 4x^3
x = 1.5536x10^-4 M <<< solubility of the pure substance
= = = = = = = == = = = = = = = == = =
pH of a sat. solution
[OH(-)] = 2x = 3.1072x10^-4 M
pOH = 3.5 ... pH = 10.5