Barrons SAT Subject Test Chemistry, 13th Edition

The chart below summarizes the colligative effect for aqueous solutions.

Molal Freezing Point and Boiling Point Comparisons

Example 1

A 1.50-gram sample of urea is dissolved in 105.0 grams of water and produces a
solution that boils at 100.12°C. From these data, what is the molecular mass of
urea?
Because this property is related to the molality, then you must find the
number of grams in 1,000 g of water.

The boiling point change is 0.12°C, and since each mole of particles causes