What is the concentration of the Mg2 ion in solution when [CO3-2] = 0.25M given that the

Ksp= 6.82 x 10-6 for the following reaction

MgCO3-------->Mg +. CO32-

Chemistry - DrBob222, Friday, November 11, 2011 at 5:34pm
Ksp = (Mg^2+)(CO3^2-)
Substitute 0.25M for CO3^2- and solve for Mg^2+

Am I using 6.82 x 10-6 to find Mg^2+.
dont think I understand

You know Ksp(6.82E-6). You know Co3^2- (0.25M). You have only one unknown, Mg^2+. Solve for that.

you have the formula Ksp= [Mg] [CO3] and you need to substitute in.25 for CO3... And plug the Ksp in with what they gave you in the problem... algebraic equation getting Mg by itself which involves multiplying both sides by the reciprocating fraction and having a divisor. You should be able to get your answer

ok DrBob the answer i got was 2.7 x10-5 am i correct

Yes Monique that is the answer.

Yes, you are correct. In order to find the concentration of Mg^2+ ion in solution, you would use the given value of Ksp, which is 6.82 x 10^-6. The Ksp expression for this reaction is Ksp = [Mg^2+][CO3^2-].

You are given that [CO3^2-] = 0.25 M. To find [Mg^2+], you can rearrange the Ksp expression and solve for [Mg^2+]. Here's how:

Ksp = [Mg^2+][CO3^2-]
6.82 x 10^-6 = [Mg^2+][0.25]

To solve for [Mg^2+], divide both sides of the equation by 0.25:

[Mg^2+] = (6.82 x 10^-6) / 0.25

Now, you can calculate the concentration of Mg^2+ ion in solution by dividing the given Ksp value by 0.25.