he equation used to calculate the change in freezing point of a substance is
Delta T_f = K_f m
where K_f is the freezing point depression constant and m is the molality of the solution.
Which of the following states the correct reasoning for the use of molality (rather than molarity) in this equation?
In solutions, moles are not directly related to grams and the freezing point of a solution is dependent solely on the number of grams of solute.
Molality does not appear in many equations, so it is used here to distinguish this equation from other similar ones.
The equation was originally published with m as a typo, rather than M, but the values are close enough that the equation is still valid.
As the temperature of a solution changes, its volume will also change, which will affect its molarity but not its molality.
