Chemistry
posted by Angelyka on .
Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp = 2.34 × 1059, and dissociates according to
Ca10(PO4)6(OH)2(s) > 10Ca2+(aq) + 6PO43(aq) + 2OH(aq)
Solid hydroxylapatite is dissolved in water to form a saturated solution. What is the concentration of Ca2 in this solution if [OH–] is somehow fixed at 7.30 × 106 M?
I am confused as to how to solve for x with such large exponents

Ca10(PO4)6(OH)2 ==> 10Ca^2+ + 6PO4^3 + 2OH^
I would substitute
(Ca^2+) = 10x
(PO4^3) = 6x
(OH^) = 2x + 7.3E6
Ksp = (Ca^2+)^10(PO4^3)^6(OH^)^2
Ksp = (10x)^10(6x)^6(2x + 7.3E6)^2
Solve for x. You want x = (Ca^2+). 
Thank you. I think I understand how to set it up.