The freezing point of ethanol (c2h5oh) is -114.6 °c. the molal freezing point depression constant for ethanol is 2.00 °c/m. what is the freezing point (°c) of a solution prepared by dissolving 50.0 g of glycerin (c3h8o3, a nonelectrolyte) in 200 g of ethanol

Freezing point of the solution = -120.02  °C

Explanation:

When a non-volatile solute is added in a volatile solvent, then vapour pressure of the pure solvent will decrease which results in depression in freezing point.

Molal freezing point depression constant for ethanol = 2.0 °C/m

Where,

= Depression in freezing point

= Molal freezing point depression constant

m = Molality

Mass of glycerin (Solute) = 50.0 g

Molecular mass of glycerin = 92.09

Mass of ethanol (Solvent) = 200 g = 0.200 Kg

m = 2.71

Now, put the value of molality,  molal freezing point depression constant in the formula,

= 5.42  °C

Freezing point of solvent - freezing point of solution = ΔTf

-114.6 °C - freezing point of solution = 5.42  °C

freezing point of solution = -5.42 - 114.6

                                           = -120.02  °C