1. Chemistry 141 Monday, December 4, 2017 Lecture 36 Real Gases and
Chemistry 11 - Lecture 11
9/30/2009
Chemistry 141
Monday, December 4, 2017
Lecture 36
Real Gases and
Intermolecular Forces

2. Questions for today: How do gases flow from one region to another?
How do real gases behave differently from ideal gases?
How do solids and liquids differ in behavior from gases? What are the reasons for these differences?
What are the forces that hold molecules together in solids and liquids?
How do these interactions relate to the physical properties of substances?

3. Distribution of speeds

4. Speed vs. molecular mass

5. Effusion & Diffusion
Effusion is the escape of gas molecules through a tiny hole into an evacuated space.
Diffusion is the spread of one substance throughout a space or a second substance.

6. Principles of Kinetic Molecular Theory
A gas is many small particles in constant, linear motion.
The majority of the volume of a gaseous substance is empty space.
Particles collide with each other and with the walls of the container.
Intermolecular forces are negligible, other than collisions.
Total kinetic energy remains constant, though individual particles may gain or lose energy via collisions.

7. Real Gases

8. States of matter

9. Intermolecular interactions
dipole-dipole interactions
induced dipole interactions

10. Trends in dispersion forces
Higher MW leads to higher polarizability, stronger IM forces, and higher boiling points.

11. Trends in BP

12. Comparing IM forces

13. Viscosities

14. Phase changes

15. Heating curves