1 The solubility product constant for magnesium hydroxide Mg

1.      The solubility product constant for magnesium hydroxide, Mg(OH)₂, is 1.5 x 10^-11. Calculate the molar solubility of magnesium hydroxide and the pH of a saturated magnesium hydroxide solution at 25^oC.<?xml:namespace prefix = o ns = \"urn:schemas-microsoft-com:office:office\" />

Solution

molar solubility=1.5 x 10^-11.

Mg+2(OH)=x+2x

1.5 x 10^-11.=x*[2x]^2

x=1.553*10-4= molar solubility

[oh-]=2*1.553*10-4=3.107*10-4

pOH=-LOG[OH-]

=3.5

pH=14-3.5=10.5