A 1.40 M solution of CaCl₂ in water has a density of 1.11 g/mL.What is the molality? A)1.90 m CaCl₂ B)2.30 m CaCl₂ C)1.47 m CaCl₂ D)1.44 m CaCl₂

Question

Quizplus · Accepted Answer

Molality (m) is defined as the number of moles of solute per kilogram of solvent. To calculate the molality, we first need to determine the number of moles of CaCl2 in 1 kg (1000 g) of water.

Mass of CaCl2 in 1 L of solution = density x volume x molar mass
= 1.11 g/mL x 1 L x 1 mol/111 g
= 0.01 moles

Since the mass of 1 L of solution is 1.11 kg, the molality is:

m = 0.01 moles / 1.11 kg
= 0.009 moles/kg or 1.47 m CaCl2.

Therefore, the best choice is C.

A 140 M Solution of CaCl2 in Water Has a Density

A 140 M Solution of CaCl₂ in Water Has a Density