Homework Help: Chemistry

Posted by Angelyka on Thursday, January 24, 2013 at 11:18pm.

Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp = 2.34 × 10-59, 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 × 10-6 M?

I am confused as to how to solve for x with such large exponents

Chemistry - DrBob222, Friday, January 25, 2013 at 12:04am
Ca10(PO4)6(OH)2 ==> 10Ca^2+ + 6PO4^3- + 2OH^-
I would substitute
(Ca^2+) = 10x
(PO4^3-) = 6x
(OH^-) = 2x + 7.3E-6
Ksp = (Ca^2+)^10(PO4^3-)^6(OH^-)^2
Ksp = (10x)^10(6x)^6(2x + 7.3E-6)^2
Solve for x. You want x = (Ca^2+).
Chemistry - Angelyka, Friday, January 25, 2013 at 10:18pm
Thank you. I think I understand how to set it up.

Answer this Question

Related Questions

Chemistry - Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp...
Chemistry - Write the balanced equation and solubility product expression for ...
Chemistry - Write the balanced equation and solubility product expression for ...
Chemistry(Please help) - What is the molar solubility of barium phosphate in a 0...
Chemistry - What is the solubility equilibrium for Mn3(PO4)2? Isn't it this...
chemistry - If the concentration of Pb2+ is found to be 2.3 x 10-9 mol/L in a ...
Chemistry - Can you give me an example of a compound that can make Ba3(PO4)2 ...
Chemistry - My teacher uses the online homework ARIS and the question is write ...
Chemistry - Balance the following chemical equation. __Fe(OH)2 (s) + __H3PO4 (aq...
chemistry - caculation: 2Na3PO4(aq)+3BaCl2(aq)-> 6NaCl(aq)+Ba3(PO4)2(s) a...

For Further Reading

First Name:
School Subject:
Answer: