Question

What is the molality of a solution of Fe(ClO3), in water that freezes at -2.72°C?

Answer 1

Answer:

0.366m = Molality of the solution

Explanation:

To solve this question we must know the addition of a solute produce decreasing in freezing point regard to the pure solvent. The equation is:

ΔT = m*Kf*i

Where ΔT is change in freezing point

(As freezing point of water is 0°C, the ΔT is 2.72°C)

Kf is freezing point depression constant = 1.86°C/m for water

i is Van't Hoff factor. The number of ions produced when 1 mole of the salt is dissolved = 4 ions for Fe(ClO₃)₃, Fe³⁺ and 3 ClO₃⁻ ions

m is molality of the solution.

Replacing:

2.72°C = m*1.86°C/m*4

0.366m = Molality of the solution