# Chemistry - Posted for Rudy

Posted by Rudy on Sunday, January 26, 2014 at 7:24pm.

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 4.30 × 10-6

I understand to set this question up as such:
2.34e-59 = (10x)^10(6x)^6(4.3e-6+2x)

But I don't understand the next step, can anyone help? you don't have to give the answer just the next few steps

1. 👍 0
2. 👎 0
3. 👁 515
1. wouldn't the Ca ion cncentration be 5 times the OH conc?

1. 👍 0
2. 👎 0
2. First, I think you left a squared term off the OH^-.
Ca10(PO4)6(OH)2(s) --> 10Ca2+(aq) + 6PO43-(aq) + 2OH-(aq)

(Ca^2+) = 10x
(PO4^3-) = 6x
(OH^-) = 2x

Ksp = (Ca^2+)^10(PO4^3-)^6(OH^-)^2

Substituting the x values we have
Ksp = (10x)^10(6x)^6(4.3e-6 + 2x)^2
I would make the assumption that
4.3e-6 + 2x = 4.3e-6 so we have
Ksp = (10x)^10(6x)^6(4.3e-6)^2
2.34e-59 = 10^10*x^10 (6x)^6*(1.85e-11)
2.34e-59 = 10^10*x^10*4.66e4*x^6*(1.85e-11)
2.34e-59/[(10)^10*(4.66e4)*(1.85e-11) = x^16.

1. 👍 0
2. 👎 0

## Similar Questions

1. ### Chemistry

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

asked by Gabby on January 19, 2013
2. ### Chemistry

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

asked by Angelyka on January 24, 2013
3. ### Chemistry

Hydroxylapatite, Ca10(PO4)6(OH)2, has a solubility constant of Ksp = 2.34 × 10^-59. Solid hydroxylapatite is dissolved in water to form a saturated solution. What is the concentration of Ca2 in this solution if [OH–] is somehow

asked by C on April 4, 2013
4. ### Chemistry

Hydroxyapatite, Ca10(PO4)6(OH)2Ca10(PO4)6(OH)2 , has a solubility constant of Ksp = 2.34×10−592.34×10−59 , and dissociates according to Ca10(PO4)6(OH)2(s) --> 10Ca2+(aq) + 6PO4^3-(aq) + 2OH-(aq) Solid hydroxyapatite is

asked by TS on November 3, 2018
5. ### Math 221

Math 221 - Ms. Sue, Sunday, July 13, 2014 at 2:24pm I've done several problems for you. Now it's your turn. How do you think this problem should be solved? Answer this Question I was thinking that I should multiply the numerators

asked by Erica on July 13, 2014
6. ### English

Thank you for your help. Posted by rfvv on Sunday, March 16, 2014 at 3:35pm. 1. What's she like? - She's really tall. 2. What's the boy like? - He is cute. 3. What's she like? - She is handsome. (Are they grammatical?) English -

asked by rfvv on March 16, 2014
7. ### math fractions

•math - Ms. Sue, Sunday, November 16, 2014 at 12:39pm 12 •math - bob, Sunday, November 16, 2014 at 12:56pm Ms. Sue can you tell me how you got that answer please. •math - Ms. Sue, Sunday, November 16, 2014 at 1:09pm

asked by bob on November 16, 2014
8. ### algebra 2

Posted by hellogoodbie on Saturday, January 16, 2010 at 3:24pm. Posted by hellogoodbie on Saturday, January 16, 2010 at 2:59pm. How is this problem done? IF f(x)=2x^2-8x-3 FIND f(-2) algebra 2 - bobpursley, Saturday, January 16,

asked by hellogoodbie on January 16, 2010
9. ### Chemistry

Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3(PO4)2: i thought the answer was Mn3(PO4)2 (s) = Mn^2+(aq) + (PO4)2 ^3- (aq) but that's not right. then for the Ksp expression i

asked by Jake on November 30, 2010
10. ### Chemistry

Write the balanced equation and solubility product expression for the solubility equilibrium of Mn3(PO4)2: i thought the answer was Mn3(PO4)2 (s) = Mn^2+(aq) + (PO4)2 ^3- (aq) but that's not right. then for the Ksp expression i

asked by Jake on December 1, 2010

More Similar Questions