Objectives

After finishing this activity, you should be able to:

1. define molality
2. derive an equation useful for molality calculations, from the definition of molality
3. do calculations where the concentration is expressed as molality including calculating:
   1. the molality of a solution
   2. the number of moles of a component present in a specified amount of a solution
   3. the mass of solvent and component needed to make up a volume of solution of specified molality.

Prerequisites

You need to know the following:
the basic units of mass and volume; the relationship between number of moles, RMM and mass and how to do the associated calculations; what significant figures are.

You will probably need a calculator.