Be(OH)2 + H2O ---> ?

[doubledoctordoubletrouble]

This question is from a TPR FL test.

How many moles of Be(OH)2 (s) must be added to one liter of water in order to create a saturated solution if the Ksp of Be(OH)2 (s) is 6.92*10^-22.

The answer key just tells me to start with the balanced equation, but I'm not exactly sure how Be(OH)2 reacts with water...

Edit: Oh wait... does it simply dissolve?
Please excuse my stupidity, I am quite burnt out from studying...

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[doubledoctordoubletrouble]

Okay, yes-- Be(OH)2 dissolves into the respective ions.
However, to get to the correct numerical answer, I have to calculate the cubed root of 1.73 * 10^-22. Is that even a reasonable calculation to ask of us...?

 

[erythrocyte666]

Okay, yes-- Be(OH)2 dissolves into the respective ions.
However, to get to the correct numerical answer, I have to calculate the cubed root of 1.73 * 10^-22. Is that even a reasonable calculation to ask of us...?

depends how close answer choices are. but you can still estimate by doing 173 x 10^-24 --- cube root of this is a little over 5.5 x 10^-8 (since 173 is a little over halfway b/w 5^3 and 6^3)