What is the molality of a water solution that contains a non-volatile solute and freezes at -2.25 degrees Celsius? The freezing point depression constant for water Kf is 1.86 degrees Celsius per mole.

Question

2419 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-11-25T23:23:28

The molality of this solution is approximately #1.21m#.

We know the #T_f = 0°C# for water.

Hence, #DeltaT_f = 2.25#. Moreover, nonvolatile solutes' van't Hoff factor is generally 1.

And, #DeltaT_f = iK_fm#

We'll do our calculation given those variables, as such

#2.25°C = 1 * (1.86°C)/(m) * m#
#therefore m = 1.21m#