Molecular weight determination from freezing point depression Which is the better solvent for molar mass determinations by freezing point depression, benzene or cyclohexane?
  Which is the better method for molar mass determination, freezing point depression or boiling point elevation?
  


What is the correct approach for solving these?


In my opinion, resonance structures might be the key concept, but I don't know how it would help or hurt.
I think boiling has a decomposing effect that we must avoid, meaning freezing the compound(s) is preferable.


But, both of these statements are inadequate.
Molar freezing point depression  
Benzene      5.12 °C/m  
Cyclohexane  20.0 °C/m  

Molar boiling point elevation  
Benzene      2.53 °C/m  
Cyclohexane  2.79 °C/m  


I would base my argument on the constants, instead of waving hands.