Question

Need help with freezing point depression expeiment

volume of acetic acid 30
volume of unknown solute in solution1    1.5
volume of unknown solute in solution 2 1.5
freezing point of pure acetic acid 16.3
freezing point of solution 1 14.5
freezing point of solution 2 11.3
average molar mass of unknown solute

Calculations for Part 1

The density of acetic acid is 1.049 g/mL and Kf(acetic acid) =3.90 °C·kg/mol

The density of the unknown is 0.791 g/mL.

1.Calculate the masses of the solvent and/or solute present in each of the three samples.

2.Calculate the freezing point depression (|ΔTf|) for the two solutions.

3.Calculate the experimental value of the molality (moles of solute per kg solvent)

of the two solutions based on the |ΔTf for the two solutions.

4.Calculate the experimental value for the moles of solute present in each solution.

5.Calculate the molar mass (grams per mole) of the unknown solute.

6.Calculate the average molar mass of the unknown solute based on the values

obtained from the two solutions.