Freezing Point Depression Lab

Attempts to correctly record and report data

Remember Colligative Properties

Tf = i Kf m molality = moles of solute (unknown) kg of solvent (nonpolar solvent)

Solvent = 2,6-ditertbutyl-4-methylphenol

Mixture = Solvent + Unknown Compound

POSSIBLE UNKNOWNSStearic Acid para-Dicholorobenzene Naphthalene

View your collected data for SOLVENT

Compare your experimental to the actual reported on the board

View your collected data for the MIXTURE

View your collected data for the MIXTURE

Draw two best fit lines from the two separate portions of the curves.

View your collected data for the MIXTURE

1. Calculate Tf - Plug in.

2. Use the accepted Kf

3. Solve for m of the solution mixture.

4. Use m to solve for moles of unknown solute.

5. Use moles to calculate molar mass. 6. ID the unknown.

Using the data! Tf = Kf m molality = moles of solute (unknown) kg of solvent (nonpolar solvent)