[Tutorial: Colligative Calculations]: This tutorial will guide you through calculating the boiling point elevation and freezing point depression for an ideal solution. Consider the boiling point and freezing point for a solution made from 13.1g of ethanol (MM 46.07g/mol ) in 100.0mL of water (density 1.00 g/mL) Step 2. Calculate molality. The molality of the solution will have the units of mol ethanol /kg water. Calculate the molality of the solution made from 13.1g ethanol (MM 46.07g/mol ) in 100.0mL of water (density 1.00g/mL ). Remember to divide by the kilograms of just water