What is the difference between the concentration terms of #"molarity"#, and #"molality"#?

1 Answer
Jul 3, 2017

Answer:

At low concentrations they are equivalent.........

Explanation:

As you know, we define these concentrations as:

#"Molarity"="Moles of solute"/"Volume of solution"#, and thus molarity typically has the units of #mol*L^-1#.

On t'other hand.........

#"Molality"="Moles of solute"/"Mass of solution (kg)"#, and thus molality typically has the units of #mol*kg^-1#.

To make the conversion, we would typically require the #"density"# of the solution, #rho_"solution"#...........so that we can assess the volume of the solution...........

See here for a model calculation.