Question

10. Use the accepted Ksp value of Calcium hydroxide to calculate the following:

a. What is the most calcium hydroxide that can be dissolved in 1.0 Liters of de-ionized water?

b. What is the most calcium hydroxide that can be dissolved in 125.0 ml of de-ionized water?

c. What is the most calcium hydroxide that can be dissolved in 287.0 ml of
de-ionized water ?

Answer 1

.......Ca(OH)2 ==> Ca^2+ + 2OH^-
I......solid.......0........0
C......solid........x.......2x
E......solid.......x........2x

Ksp = (Ca^2+)(OH^-)^2
Substitute the E line into the Ksp expression and solve for x. That will give you the solubility of Ca(OH)2 in mols/L. That is part a in mols/L. If you want grams, that is g = mols x molar mass = ?
part b.
?mols/L x (125/1000) = ? mols/125 mL

part c.
c is a repeat procedure of b.