calculate the molar solubility of FeCO3. How many grams of FeCO3 are present in 15 L of a saturated FeCO3 solution ?
FeCO3 ==> Fe^2+ + CO3^2-
...x.......x.......x
Ksp = (Fe^2+)(CO3^2-)
Substitute and solve for x. Units are mols/L; then mol/L x 15 L = total mols and
grams/molar mass converts to grams.
To calculate the molar solubility of FeCO3, we need to determine the concentration of FeCO3 in moles per liter (mol/L) at equilibrium. The molar solubility is the number of moles of a substance that dissolve to form a saturated solution in one liter of solvent at a certain temperature.
To find the molar solubility of FeCO3, we need to know the solubility product constant (Ksp) of FeCO3. Given that the solubility product constant for FeCO3 is 4.87 × 10^(-11), we can set up an equilibrium expression:
FeCO3(s) ⇌ Fe2+(aq) + CO3^2-(aq)
The equation suggests that one mole of FeCO3 produces one mole of Fe2+ and one mole of CO3^2-. Therefore, the molar solubility of FeCO3 is equal to the concentration of Fe2+ and CO3^2- in the saturated solution.
Let's assume the molar solubility of FeCO3 is "x" mol/L. From the balanced equation, we can see that the concentration of Fe2+ and CO3^2- in the saturated solution is also "x" mol/L.
Now, we can write the expression for the solubility product constant (Ksp):
Ksp = [Fe2+][CO3^2-]
Substituting the values into the equation, we get:
4.87 × 10^(-11) = (x)(x)
To solve for "x," we take the square root of both sides:
√(4.87 × 10^(-11)) = x
x ≈ 6.97 × 10^(-6) mol/L
So, the molar solubility of FeCO3 is approximately 6.97 × 10^(-6) mol/L.
Now, to calculate the grams of FeCO3 present in 15 L of the saturated solution, we can use the molar mass of FeCO3.
The molar mass of FeCO3 is calculated as follows:
Fe: 55.85 g/mol
C: 12.01 g/mol
O: 16.00 g/mol (three oxygen atoms in FeCO3)
Total molar mass = 55.85 + 12.01 + (16.00 × 3) = 115.85 g/mol
To calculate the grams of FeCO3 in the solution, we can multiply the molar solubility by the molar mass and volume of the solution:
Grams of FeCO3 = (6.97 × 10^(-6) mol/L) × (115.85 g/mol) × (15 L)
Calculating this expression will give you the grams of FeCO3 present in the 15 L of the saturated FeCO3 solution.