Of state. Contents and Concepts 1. Comparison of Gases, Liquids, and Solids Changes of State

11.4 Properties of Liquids; Surface Tension and Viscosity

You have seen that molecules tend to escape the liquid state and form a vapor. The vapor pressure is the equilibrium partial pressure of this vapor over the liquid; it increases with temperature. The boiling point is the temperature at which the vapor pressure equals the pressure applied to the liquid. Both vapor pressure and boiling point are important properties of a liquid. Values of the vapor pressure for some liquids at 20_C are listed in Table 11.2 (column 3). Two additional properties given in

Table 11.2 are surface tension and viscosity. All of these properties, as you will see in the next se