Experiment 8: Freeing Point Depression of Lauric Acid Flashcards
1
Q
Freezing point depression is caused by…
A
Impurites in the substance
2
Q
delta T=
A
delta T=Kf*m,
Kf= freezing point depression of the solvent
m=molality=moles solute / mass solvent
3
Q
The impurity we used is
A
Benzoic acid
4
Q
Why do we use molality?
A
Neither moles nor mass are effected by temperature
5
Q
Procedure:
A
1) Melt and refreeze pure lauric acid, lauric with .75 g benzoic, and lauric with 1.5g benzoic
6
Q
The freezing/melting point is the____.
A
The y intercept of the flat portion of the graph.
7
Q
Molality =
A
moles solute/kg solvent
8
Q
What is the difference between freezing/melting point?
A
No numerical difference, only a phase change difference
9
Q
Solute and solvent we used?
A
Benzoic acid, Lauric acid
10
Q
Do we consider the can’t hoff factor?
A
No (non electrolyte)
