I need to find out Molar solubility of CuS. How many grams of CuS are present in 15.0 L of a saturated CuS solution,
...............CuS ==> Cu^2+ +S^2-
equilibrium..............x.....x
Ksp = (Cu^2+)(S^2-)
Ksp = (x)(x)
Solve for x which gives you the molar solubility (that's moles/L)
grams/L = moles x molar mass
Then you want grams/15 L so multiply by 15.
To find the molar solubility of CuS, we need to determine the number of moles of CuS present in the given volume of the solution. Here are the steps to calculate it:
1. Look up the molar mass of CuS.
The molar mass of CuS can be calculated by adding the atomic masses of copper (Cu) and sulfur (S). The atomic mass of copper is 63.55 g/mol, and the atomic mass of sulfur is 32.06 g/mol. Therefore, the molar mass of CuS is 63.55 + 32.06 = 95.61 g/mol.
2. Calculate the number of moles of CuS.
Since we have the volume of the solution (15.0 L), we also need to know the molarity of the saturated CuS solution. The molarity is usually given in units of moles per liter (mol/L) or molar (M).
If you have the molarity of the solution, you can directly multiply it by the volume in liters to obtain the number of moles.
However, if you don't have the molarity, we will need more information, such as the solubility product constant (Ksp) of CuS.
The solubility product constant is the equilibrium constant for the dissolution of an ionic compound in water. It is a measure of the solubility of the compound.
Without the solubility product constant (Ksp), it is challenging to determine the molar solubility of CuS precisely.
3. Use the solubility product constant (Ksp) to calculate the molar solubility.
The Ksp expression for the dissolution of CuS is: Ksp = [Cu2+][S2-].
Since the compound is CuS, we can assume that one mole of CuS dissociates into one mole of Cu2+ and one mole of S2- ions in solution.
Therefore, at equilibrium, the concentrations of Cu2+ and S2- are equal, and each is equal to the molar solubility of CuS, denoted as "s." So, [Cu2+] = [S2-] = s.
Substitute these values into the Ksp expression: Ksp = s * s.
If you have the solubility product constant (Ksp) for CuS, you can directly calculate the molar solubility (s) by taking the square root of Ksp.
However, if you don't have the Ksp, it is challenging to calculate the exact molar solubility of CuS in the given volume of the solution.
In conclusion, to determine the molar solubility of CuS, you need to know either the molarity of the solution or the solubility product constant (Ksp) for CuS. Without this information, it is not possible to calculate the exact molar solubility of CuS in the given volume.