13.2. Liquids http://www.ck12.org
13.2 Liquids
Lesson Objectives
- Describe a liquid according to the kinetic-molecular theory.
- Describe how a liquid exhibits surface tension.
- Describe the evaporation of a liquid and its relationship to the kinetic energy of the evaporating particles.
- Define vapor pressure and understand its relationship to intermolecular forces and to the temperature of the
liquid. - Describe the process of boiling and differentiate between boiling point and normal boiling point.
- Use a vapor pressure curve to determine boiling points at different atmospheric pressures.
Lesson Vocabulary
- boiling point
- condensation
- evaporation
- fluid
- normal boiling point
- surface tension
- vapor pressure
- vaporization
Check Your Understanding
Recalling Prior Knowledge
- What is the kinetic-molecular theory?
- What makes gases different from liquids and solids?
Gases are easy to study because of the extremely large distances between the gas particles. Because there is so much
space between particles, intermolecular forces can largely be ignored, which vastly simplifies any analysis of the
motion exhibited by individual particles. In this lesson, we begin to study the properties of liquids and discover the
importance of a liquid’s intermolecular attractive forces.
15.1 Properties of Water
The primary difference between liquids and gases is that the particles of a liquid are much closer together, and there
is very little empty space between them. Liquids are essentially not compressible and are far denser than gases.