[neonocto]

I'm just gonna jump right in here and throw this down:

What is the molarity of a Ca(OH)₂ solution whose pH=11?

I have also found the Ksp of the solution to be 6.5x10^-6, but how this is helpful to me I'm unsure.

There is also a similar problem with the pH=11.88, where I can only assume the process is the same.
I was able to determine the molarity of a HCl solution given pH, but that is only because the [H+] concentration is the same as the molarity with strong acids, so I just did 10 raised to the power of the pH. Is that process helpful in this regard, or am I hopelessly off-track?
Any assistance is appreciated.

[Borek]

What is concentration of OH^- in a solution with pH 11?

[neonocto]

Well 14-pH=pOH which is 14-11=3, and 10^-3 = .001, but the final answer I'm supposed to be getting to is 0.0005.
I've been seeing where people are doing Ksp=(1.0 x 10^-pH)²/(HZ/HC), which would end up being 6.5x10^-6=(1.0x10^-11)²/(HC)
Then being (1.0x10^-11)²/(6.5x10^-6)²
But the answer that got me was nowhere near the 0.0005 I'm trying to get to. I could be making this entirely too complicated.

[sjb]

Well 14-pH=pOH which is 14-11=3, and 10^-3 = .001, but the final answer I'm supposed to be getting to is 0.0005.

Is the concentration of Ca(OH)₂ the same as that of OH^-?