A water solution containing an unknown quantity of a nonelectrolyte solute is found to have a freezing point of

–0.23°C. What is the molal concentration of the solution?​

The molal concentration of the solution is approximately 0.124 molal

Explanation:

The given parameters are;

The reduced freezing point of the water = -0.23°C

For freezing point depression of a solution, we have;

= · b·i

Where;

= The freezing point depression

= Cyroscopic constant (The freezing-point depression constant) = 1.86° Cm⁻¹ for water

b = The molality of the solution

i = van't Hoff factor = 1

Therefore;

=

Where;

= The freezing point of pure water = 0°C

= The freezing point of the solution = -0.23°C

∴ = = 0°C - (-0.23°C) = 0.23 °C

From, = · b·i, we have;

0.23°C = 1.86°C/m × b × 1

∴ b  = (0.23°C/1.86°C/m) ≈ 0.124 molal

Therefore, the molal concentration of the solution, b ≈ 0.124 molal.

water and alcohols have similar properties because water molecules contain hydroxyl groups that can form hydrogen bonds with other water molecules and with alcohol molecules, and likewise alcohol molecules can form hydrogen bonds with other alcohol molecules as well as with water.