colligative property
From Glossary of Meteorology
One of four characteristic properties of solutions, namely, the interdependent changes in vapor pressure, freezing point, boiling point, and osmotic pressure, with a change in dissolved matter.
If, under a given set of conditions, the value for any one property is known, the others may be computed. In general, with an increase in dissolved matter (e.g., salt in water), freezing point and vapor pressure decrease, and boiling point and osmotic pressure increase.