Essential Questions How does the Kinetic molecular theory explain the behavior of gases? How does the kinetic molecular theory explain the phase changes of matter? What is the relationship that exists between pressure, temperature, volume and number of particles in an ideal gas? How do the gas laws relate to my real life experiences? How is the behavior of gases crucial to life on earth?

Kinetic Molecular Theory Kinetic – motion Molecular – having to do with molecules (particles) Theory – a generalization or explanation of a body of events or phenomena

History of KMT Late 1800’s scientists created a theory to account for the behavior of atoms and molecules that make up matter. The history of chemistry was founded on experimentation and observation. Scientists built upon one another’s findings.

Kinetic Molecular Theory Ideal Real Complies to the “model” description of something Perfect May exist under certain conditions Rare Hypothetical what exists out in the world Not perfect Most common

5 assumptions of KMT 1. Gases consist of large numbers of tiny particles that are far apart relative to their size. 2. Collisions between gas particles and between particles and container walls are elastic collisions. An elastic collision has no net loss of total kinetic energy

5 Assumptions of KMT 3. Gas particles are in continuous, rapid, random motion. 4. There are no forces of attraction between gas particles. 5. The temperature of a gas depends on the average kinetic energy of the particles of gas

The Nature of Gases Expansion Fluidity – able to flow, like when I poured the gases Low density Compressibility

KMT Although the kmt deals with “hypothetical, ideal” gases, some gases come very close to ideal behavior under certain conditions. Noble gases are more likely to act like ideal gases because they have little attraction for each other. Other conditions, high temp and low pressure

Diffusion The spontaneous mixing of the particles of two substances caused by their random motion.

Effusion The process by which gas particles pass through a tiny opening

Apply Using the postulates of the kinetic molecular theory, explain very specifically how the fragrance from the candle at one end of the room is able to be smelled throughout the room. (How and why did it travel?)