A solution is prepared by dissolving 15.0 g of NH₃ in 250.0 g of water. The density of the resulting solution is 0.974 g/mL. The molality of NH₃ in the solution is __________.

Question

Quizplus · Accepted Answer

Molality is calculated as moles of solute per kilogram of solvent. Moles of NH3 = 15.0 g / 17.03 g/mol = 0.880 moles. Mass of water = 250.0 g = 0.250 kg. Molality = 0.880 moles / 0.250 kg = 3.52 mol/kg, which rounds to 3.53.

A Solution Is Prepared by Dissolving 15