A 3.38 molar solution of cesium chloride (molar mass = 168.4 g/mol) has a density of 1.423 g/mL. What is the molality of the solution?

Question

Quizplus · Accepted Answer

Molality is defined as moles of solute per kilogram of solvent. To find the molality of the solution, we need to first calculate the number of moles of cesium chloride present in one liter of solution, which is equivalent to 1,423 grams (since the density of the solution is given as 1.423 g/mL).

Number of moles of cesium chloride = (3.38 mol/L) x (1 L) = 3.38 moles

Mass of cesium chloride present in 1 L of solution = (3.38 moles) x (168.4 g/mol) = 569.192 g

Now, we need to convert the mass of cesium chloride in 1 L of solution to kilograms:

Mass of cesium chloride in 1 L of solution = 569.192 g = 0.569192 kg

Therefore, the molality of the solution is:

molality = (moles of solute) / (mass of solvent in kg)
molality = (3.38 mol) / (0.569192 kg) = 5.9362 m

Therefore, the correct answer is B) 3.96 m.

A 338 Molar Solution of Cesium Chloride (Molar Mass = 168