Week 5 Lesson - Gas Laws and Kinetic Molecular Theory

Introduction

This week, we will explore the behavior of gases and the kinetic molecular theory. We will learn about the various gas laws that describe the relationships between pressure, volume, temperature, and amount of a gas. We will also discuss the assumptions of the kinetic molecular theory and how it explains the properties of gases.

Gas Laws

Boyle's Law

Boyle's law states that the pressure and volume of a gas are inversely proportional at constant temperature and amount of gas. Mathematically, this can be expressed as: P1V1 = P2V2

Charles's Law

Charles's law states that the volume of a gas is directly proportional to its absolute temperature at constant pressure and amount of gas. Mathematically, this can be expressed as: V1/T1 = V2/T2

Gay-Lussac's Law

Gay-Lussac's law states that the pressure of a gas is directly proportional to its absolute temperature at constant volume and amount of gas. Mathematically, this can be expressed as: P1/T1 = P2/T2

Avogadro's Law

Avogadro's law states that the volume of a gas is directly proportional to the amount of gas (in moles) at constant pressure and temperature. Mathematically, this can be expressed as: V1/n1 = V2/n2

Ideal Gas Law

The ideal gas law combines the four gas laws into a single equation: PV = nRT, where P is pressure, V is volume, n is the amount of gas in moles, R is the universal gas constant, and T is the absolute temperature.

Kinetic Molecular Theory

The kinetic molecular theory makes the following assumptions about gases:

  1. Gases consist of small particles (molecules or atoms) that are in constant random motion.
  2. The volume of the gas particles is negligible compared to the total volume of the gas.
  3. The particles of a gas do not attract or repel each other.
  4. Collisions between gas particles and the container walls are perfectly elastic.
  5. The average kinetic energy of gas particles is directly proportional to the absolute temperature.

These assumptions help explain the behavior of gases and provide a foundation for understanding the gas laws.