Answer:
Ksp = 2.06x10⁻¹⁰
Step-by-step explanation:
For AB₂. solubility product constant, Ksp, is written as follows:
AB₂(s) ⇄ A²⁺ + 2Br⁻
Ksp = [A²⁺] [Br⁻]²
Molar solubility represents how many moles of AB₂ are soluble per liter of solution. and is obtained from Ksp:
AB₂(s) ⇄ A²⁺ + 2Br⁻
AB₂(s) ⇄ X + 2X
where X are moles that are soluble (Molar solubility)
Ksp = [X] [2X]²
Ksp = 4X³
As molar solubility of the salt is 3.72x10⁻⁴M:
Ksp = 4X³
Ksp = 4(3.72x10⁻⁴)³
Ksp = 2.06x10⁻¹⁰