Magnesium hydroxide is an
inorganic compound with the chemical formula of hydrated Mg(OH)
2. It is often known as
milk of magnesia, because of its milk-like appearance as a
suspension. While magnesium hydroxide has a low solubility in water, with a
Ksp of 1.5×10
-11, it is large enough that it will partially dissolve to produce ions in the solution, forming the suspension. A relatively high concentration of magnesium or hydroxide ions would be required to revert the suspension to the solid precipitate by reversing the equilibrium.