How can I calculate molality of an aqueous solution?

1 Answer
May 12, 2014

Molarity = moles of solute/ kilograms of solvent.

The solvent in this case is water because you want to create an aqueous solution.

Here is an example. If you want to make 1.0 kilogram of 0.50 glucose solution, how would you prepare it?

Measure 90.0 grams of glucose which gives you 0.50 moles.

The formula of glucose is C6H12O6.

90.0 grams/180 grams = 0.50 moles

If you divide 90.0 grams of solute by the molar mass of glucose (180 g/mol) you obtain 0.50 moles

Dissolve 90.0 grams of solute into 1.0 kilogram of water to obtain 0.50 molar solution of glucose