An aqueous solution is 0.387 mol L^-1 in HCl. What is the molality of the solution if the density is 1.23 g mL^-1? A) 0.115 mol kg^-1 B) 0.387 mol kg^-1 C) 0.315 mol kg^-1 D) 0.411 mol kg^-1 E) 0.318 mol kg^-1

Question

Quizplus · Accepted Answer

To find molality, we need moles of solute per kg of solvent. First, find the mass of 1 L of solution: 1.23 g/mL * 1000 mL = 1230 g. The mass of HCl in 1 L is 0.387 mol * 36.46 g/mol = 14.1 g. The mass of water is 1230 g - 14.1 g = 1215.9 g = 1.2159 kg. Molality = 0.387 mol / 1.2159 kg = 0.318 mol/kg.

An Aqueous Solution Is 0