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## Homework Statement

What is the solubility of Mg(OH)2 in a solution buffered at pH 8.80.

## Homework Equations

## The Attempt at a Solution

The answer is .45 M or 26 g/L but I can't get that for some reason.

I can find the concentration of hydroxide [OH-] = 6.3 x 10-6

Mg(OH)2 -> Mg+2 + 2OH-

................0+x,....6.3x10-6 + 2x

1.8x10-11 = x(6.3x10-6 + 2x)^2

x = 1.65 x 10-4 M (neglecting the 6.3 x10-6)

I've also tried solving the cubic with similar results.

Does anyone where I went wrong?