Answer to Question #71220 in General Chemistry for Jo

Question

The molecular mass of Aspirin is 180. Aspirin has a solubility of 15mg/ml at room temperature. What is the molar concentration at this solubility? Give your answer to 3 decimal places.

Answer 1

Molar concentration = Moles of solute (n) / Volume of solution (L), so if solubility of aspirin is 15 mg/ml (room temperature), there is solubility in g/l equal to 15 g/L (1 g = 1000 mg and 1 L = 1000 ml. Solution of aspirin with a volume of 1 liter contains 15 grams of substance. Number of moles of substance is mass of substance / molar mass of substance = 15 g / 180 g/mol = 0.083 mol. So for this level of solubility, molar concentration is 0.083 mol/L (or 8.333·10-5 mol/ml)

Answer: 0.083 mol/l