Chemistry States of Matter Kinetic Molecular Theory

1. ChemistryStates of MatterKinetic Molecular Theory CALCULATORS NOT REQUIRED PERIODIC TABLES NOT REQUIRED

2. Kinetic-Molecular Theory • This is a model that aids in our understanding of what happens to gas particles as environmental conditions change. • This determines what is an ideal gas.

3. Main Tenets of Kinetic-Molecular Theory • The combined volume of all molecules of the gas is negligible relative to the total volume in which the gas is contained. • In other words, the volume of the gas molecules themselves doesn’t matter.

4. Main Tenets of Kinetic-Molecular Theory • Attractive and repulsive forces between gas molecules are negligible.

5. Main Tenets of Kinetic-Molecular Theory • Energy can be transferred between molecules during collisions, but the average kinetic energy of the molecules does not change with time, as long as the temperature of the gas remains constant.

6. Main Tenets of Kinetic-Molecular Theory • The average kinetic energy of the molecules is proportional to the temperature.

7. Pressure and Temperature • Pressure, then, is defined by how often gas molecules hit the sides of their container. • Temperature has to do with how quickly the gas molecules are moving.

8. Diffusion • Diffusion is the spread of one substance throughout a space or throughout a second substance. • (J-LO and Food Coloring Demos) • Caused by the random motion of molecules.

9. Limitations of Kinetic Molecular Theory • KMT assumes that all gases are identical and have no attractive forces. Intermolecular forces are not included. • KMT works best for light gasesat high temperature and low pressure (gas moves fast and is spread out) • Although KMT works only for ideal gases, corrections for real gases are very complicated and many gases can be approximated as ideal.