If a substance X has a solubility of 1.9×10−4 mg L−1, and a molar mass of 132 g mol−1, what is the molar solubility of the substance?

Question

If a substance X has a solubility of 1.9×10−4 mg L−1, and a molar mass of 132 g mol−1, what is the molar solubility of the substance?

Answer 1

So, what does molar solubility mean? It means how many moles are soluble in 1 liter of solution. You are given the mass (1.9x10^-4 mg) that is soluble in 1 liter, so all you need to do is convert this mass into moles.

1.9x10^-4 mg x 1 g/1x10³ mg x 1 mole/132 g = 1.4x10^-9 moles

Molar solubility = 1.4x10^-9 moles/liter = 1.4x10^-9 M