Kinetic Molecular Theory (KMT) Overview

Kinetic Molecular Theory (KMT)

• KMT describes the experimentally discovered behavior of particles, applicable to gases, solids, and liquids.

Characteristics of Solids, Liquids, and Gases

• Solids: molecules are tightly packed, gently sway in place, and are not affected by the shape or volume of the container.
• Liquids: molecules have more space between them, move faster than solids, and flow past other molecules, taking the shape of the container.
• Gases: molecules have the most space between them, move the fastest, and take on both the shape and volume of the container.

Changes between Phases

• A substance can change from one phase to another by overcoming intermolecular dipole-dipole forces.
• Kinetic energy weakens dipole-dipole forces, allowing molecules to break bonds and change phase.

Assumptions of Kinetic Molecular Theory

• Gases are composed of particles in random, constant motion.
• Gas molecules move in a straight line until they collide with something.
• Gas molecules are not attracted to one another or to the container.
• Collisions between gas molecules are perfectly elastic.
• The average kinetic energy of a collection of gas particles depends only on the temperature of the gas.

Kinetic Molecular Theory and Gas Laws

• Ideal Gas Law: PV = nRT, relates pressure, volume, temperature, and amount of a gas.
• Boyle's Law: P1V1 = P2V2, relates pressure and volume of a gas when all other factors are held constant.
• Charles' Law: T1/V1 = T2/V2, relates temperature and volume of a gas when all other factors are held constant.

Kinetic Energy

• Kinetic energy is the measurement of the magnitude of an object's motion, usually recorded in Joules.
• KE = (3/2) RT, calculates kinetic energy of an ideal gas.
• Kinetic energy varies greatly between phases: solids (lowest), liquids (moderate), and gases (highest).

Real-World Examples of KMT

• Car tires inflate/deflate depending on temperature, due to changes in kinetic energy.
• Breathing in and out, lung volume and pressure changes demonstrate KMT through Boyle's Law.

Explore the fundamental concepts of Kinetic Molecular Theory (KMT) and understand how it describes the behavior of particles in gases, solids, and liquids. Learn about the movement and interactions of molecules in different states of matter.