Can I find the molality of a solution if I have the molarity and the density?

Expert Answers
justaguide eNotes educator| Certified Educator

Molality is a way of measuring the concentration of a compound dissolved in a solution. If a solution has a molality of one, there is one mole of the solute dissolved in one kilogram of the solution. Molarity on the other hand is concentration expressed in moles per liter of the solution.

If you have the molarity and density of a solution you can calculate the molality of the solution.

Let molality be denoted as M', M' = mol/kg and M denote molarity, M = mol/liter

Density D = kg/liter

M/D = (mol/liter)/(kg/liter) = mol/kg = M'

The molality of a solution can be derived by dividing the molarity of the solution by its density.

shihan | Student

The molality of a solution can be derived by dividing the molarity of the solution by its density.