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) 0.0449 B) 2.55 C) 12.00 D) 0.446 E) 2.32

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Quizplus · Accepted Answer

To find molality, we need moles of solute per kg of solvent. First, calculate the mass of the solution using its density (1.0344 g/mL) and volume (1 L = 1000 mL), which gives 1034.4 g. The mass of NH4Cl in 1 L is 2.32 moles * 53.50 g/mol = 124.52 g. The mass of water is 1034.4 g - 124.52 g = 909.88 g = 0.90988 kg. Molality = 2.32 moles / 0.90988 kg = 2.55 mol/kg.