Pre-Lab: Colligative Properties and Ice Cream

Pre-Lab: Colligative Properties and Ice Cream
(Total 10 Points)
Note: In preparing this report you are free to use references and consult with
others. However, you may not copy from other students’ work (including your
laboratory partner) or misrepresent your own data (see honor code).
Name(Print then sign): ___________________________________________________
Lab Partner: ____________________________________________________________
Lab Day: ___________________Section: ________TA_________________________
1. Define molality (m) and molarity (M) by writing an equation for each.
2. What is the freezing point of a solution of 13.0 g of NaCl in 225 g of water? The
molal freezing point constant for water is 1.86 Ckg / mol .
Remember: Equation for a molecule that dissociates: ΔT = iKfm
Where ΔT = Tpure – Tsolution (Tpure of solvent)
i = # ions in solution (if the solute does not dissociate i=1)
Kf = Freezing point depression constant (C/m)
m = concentration in molality (molesolute/kgsolvent)