Final answer:
The molar solubility of a substance like BaSO4 can be calculated using its Ksp value by setting up the equilibrium expression for its dissociation in water, solving for the solubility 's', and then taking the square root of the Ksp to find 's'.
Step-by-step explanation:
Calculating Molar Solubility from Ksp
To find the molar solubility of barium sulfate (BaSO4), you use the solubility product constant (Ksp) given for the substance. For BaSO4, the dissolution can be represented as BaSO4 ⇌ Ba2+ + SO42-, meaning that for every mole of BaSO4 that dissolves, 1 mole of Ba2+ ions and 1 mole of SO42- ions are produced in solution. Therefore, if 's' represents the molar solubility of BaSO4, the Ksp expression can be written as Ksp = [Ba2+][SO42-] = s2.
Given the Ksp value, you can solve for 's' by taking the square root of the Ksp. For example, if Ksp = 1.1 × 10-10 for BaSO4, then:
s = √(1.1 × 10-10)
This gives us the molarity of the saturated BaSO4 solution, which is the molar solubility of BaSO4.