Can Some PLEASE Help me with this pH Problem

I have been asking all day and really need help
Last problem that i need help on:
Determine the concentration of OH- (aq) in solution once 5 grams of solid Ba(OH)2 dissolves in H2O and attains equilibrium with it's component ions, then calculate the pH of the solution calculated above.

Ba(OH)2 (s) <----> Ba^2+^ (aq) + 2OH^-^ (aq)
Delta H= 7820 kJ (not need for this part)
Ksp of 5 x 10^-3^ (sparingly soluble)

We use the Ksp to determine the maximum solubility of Ba(OH)2

5 x 10^-3 = (x) (2x)^2

x = 0.1077 M

Now, let's determine the molarity of 5 g of Ba(OH)2

5 g / 171.3438 g/mol = 0.02918 mol of Ba(OH)2

You didn't provide a volume, let's assume 1.00 L

0.02918 mol / 1.00 L = 0.02918 M

The OH- concentration is twice the Ba(OH)2 molarity:

[OH-] = 0.05836 M

Let us calculate the pOH

pOH = - log 0.05836 = 1.234

pH = 14.000 minus 1.234 = 12.766

Update: did you notice that Erin Giggles joined today (May 10, 2011)? Personally, I don't see an F in your future. The problem you're struggling with is fairly involved; you're not struggling with the easy stuff. Email me if you get stuck. Oh, and here's my acid base stuff:

http://www.chemteam.info/AcidBase/AcidBa…

Best wishes the rest of the school year.

Enjoy your F.

You're busted.