I would like to ask 4 questions from Colligative Properties of solution experiment.
In this experiment, I used Naphthalene as solvent. Its Kf
= 7.45 C kg mol-1
1) A phenomenon called supercooling is frequently encountered in this experiment. In supercooling, a solution momentarily drops below its freezing point, and then warms up again, before solidification begins. What even is likely to give rise to supercooling?
2) The molal freezing point constant Kf
is a property of the solvent, not the solute. What does this say about the fact that freezing point depends on the amount of solute, rather than on the solute’s nature?
3) Look up the freezing point constant, Kf
for naphthalene in a handbook. How closely does your value for Kf
compare? What might have led to your obtaining a different value?
4) A phenomenon that happens sometimes during freezing point depression experiments is that the solute is affected in some manner by the solvent. One common occurrence is for a solute to dimerize; that is two solvent molecules combine to produce a single double molecule (a dimer). What effect would there be on a molecular weight determination if the solute were to dimerize?