At 20°C,a 2.32 M aqueous solution of ammonium chloride has a density of 1.0344 g/mL.What is the molality of ammonium chloride in the solution? The formula weight of NH₄Cl is 53.50 g/mol. A) 2.55 m B) 0.0449 m C) 2.32 m D) 0.446 m E) 12.00 m

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Molality (m) is defined as the number of moles of solute per kilogram of solvent. To find the molality of the ammonium chloride solution, we first calculate the mass of the solvent (water) in 1 liter of solution. Since the density of the solution is 1.0344 g/mL, the mass of 1 liter (1000 mL) of solution is 1034.4 g. The mass of ammonium chloride in 1 liter of solution is the molarity (2.32 M) times the molar mass (53.50 g/mol), which equals 124.12 g. Subtracting the mass of the solute from the total mass of the solution gives the mass of the solvent: 1034.4 g - 124.12 g = 910.28 g or 0.91028 kg. The number of moles of ammonium chloride is the molarity (2.32 M) times the volume in liters (1 L), which is 2.32 moles. The molality is then the moles of solute per kilogram of solvent: 2.32 moles / 0.91028 kg = 2.55 mol/kg.