Calculate the molar solubility of FeCO3. How many grams of FeCO3 are present in 15.0 L of a saturated FeCO3 solution?

Solution 98P :

Step 1:

Given :

Volume of saturated FeCO3 solution = 15.0 L

Grams of FeCO3 present in solution(Molar solubility) = ?

FeCO3 dissociates as :

FeCO3(s) → Fe2+ (aq) + CO32- (aq)

So, Ksp will be :

Ksp = [] []

To solve this problem, we need the solubility product, i.e Ksp for FeCO3. Assuming that the solution is at ambient temperature (25 oC), the value of the Ksp as 3.1310-11

Now, Let’s consider ‘x’ = [] and []

Therefore, Ksp = x²

(3.1310-11) = x²

x =

= 5.59410-6 M

Hence, [] and [] = 5.59410-6 M . i.e Concentration of saturated solution of FeCO3 = 5.59410-6 M.