which of the following would be expected to have the lowest freezing temperature?
a. Ca(NO3)2
b. NaC2H3O2
c. CuSO4
d. HC2H3O2
e. C2H5OH
per what? per gram? per mol? Any could have the lowest freezing point if I put a cup of any one and a scant amount of the others. For equal molality, what you want is
delta T = Kb*i*molality.
Kb is a constant, IF it is equal molality the m is equal, and the secret then is to determine the number of particles (i) from the others.