The density of a 20.3 m ch3oh (methanol) solution is 0.858 g/ml. what is the molality of this solution? h2o is the solvent.

a. 17.4 m

b. 20.8 m

c. 23.7 m

d. 70.0 m

e. 97.6 m

The difference of molarity and molality is in the units:

Molarity is expressed in mol solute / L solution;

while Molality is expressed in mol solute / kg solvent

Since no other data is given, let us assume that the contribution of methanol on the total volume is negligible. So that,

Molality = (20.3 mol / L) (1 L / 0.858 kg)

Molality = 23.66 m

The closest answer is letter C. 23.7 m