[banana1049]

What is the solubility-product constant of barium carbonate if a saturated solution is 1.1*10^-4?
I know that K_sp=[Ba][CO^2-₃], but I'm not sure where to start with this.  Should I begin by balancing the equation for BaCO₃ and then find the concentration of each part?

Just so you know, I'm not asking anyone to give me the answer to this question.  I have a final next week and I need to know how to understand problems like this.  I'm just asking for a little clarification because we raced through the last three chapters in class and I didn't quite understant everything.

[Borek]

If saturated solution is 1.1*10^-4M, what are concentrations of Ba²⁺ and CO₃^2-?

[banana1049]

Ok I ended up with

.0022g BaCO₃/100g H₂O * 1g H₂0/1ml * 1000ml/1L *1molBaCO₃/197.34g  = 1.1*10^-4

then [Ba] = [CO₃] = 1.1*10^-4
K_sp = (1.1*10^-4)² =
1.2*10^-6

[Borek]

.0022g BaCO₃/100g H₂O * 1g H₂0/1ml * 1000ml/1L *1molBaCO₃/197.34g  = 1.1*10^-4

No idea why and what, but looks OK.

then [Ba] = [CO₃] = 1.1*10^-4

OK

K_sp = (1.1*10^-4)² = 1.2*10^-6

Either error or typo.

[banana1049]

K_sp = (1.1*10^-4)² = 1.2*10^-6

Either error or typo.

[/quote]

My calculator keeps giving me 1.21*10^-6 but that's not right.  I think it's actually 1.2*10^-8.

[english]

Well your mistake is simply algebraic.  You're right.