Question

What is the freezing point (in °C) of a 0.743 m

aqueous solution of KCI?
Enter your rounded answer with
3 decimal places.
K; for water = 1.86 °C/m

Answer 1

The freezing point of a 0.743 m aqueous solution of KCl can be calculated using the freezing point depression equation. The freezing point depression is approximately -1.381 °C, so the freezing point of the solution would be -1.381 °C.

Step-by-step explanation:

The freezing point depression equation is given by

ΔTf = -Kfm

where ΔTf is the freezing point depression, Kf is the cryoscopic constant for the solvent, and m is the molality of the solution. In this case, we have a 0.743 m aqueous solution of KCl. The cryoscopic constant for water is 1.86 °C/mol. Plugging in the values, we get:

ΔTf = -1.86 °C/mol × 0.743 mol/kg

Simplifying the equation, we find that the freezing point depression is approximately -1.381278 °C. Since the normal freezing point of water is 0.0 °C, the freezing point of the solution would be

0.0 °C - 1.381278 °C = -1.381278 °C

Rounded to three decimal places, the freezing point of the solution would be -1.381 °C.