Question

A generic salt, AB, has a molar mass of 241 g/mol and a solubility of 2.60 g/L at 25 °C. What is the Ksp of this salt at 25 °C?

Answer 1

When the salt dissolves, it dissociates as follows;
AB --> A⁺ + B⁻
The molar solubility is amount of moles of the salt that can be dissolved in 1 L of solution.
solubility of the salt is - 2.60 g/L, to find molar solubility we have to multiply by the molar mass.
2.60 g/L /241 g/mol = 0.0108 mol/L
ksp = [A⁺][B⁻]
molar solubility of salt is equal to the molar solubility of cation and anion 
ksp = (0.0108)(0.0108)
ksp = 1.17 x 10⁻⁴