Kinetic Molecular Theory and Gas Laws

Flashcards covering Kinetic Molecular Theory, Gas Laws (Boyle's, Charles's, Gay-Lussac's, Avogadro's), Ideal Gas Law, and related concepts.

Kinetic Molecular Theory

A theory governing a theoretical/ideal gas, relating Kinetic Energy (KE) to the state of matter. It describes the motion and interaction of atoms/molecules.

Kinetic Energy (KE)

The energy of motion. In the context of gases, it determines the substance's state of matter and influences the interaction of gas particles.

Variables to Consider for Ideal Gases

Pressure, Volume, Temperature, and Number of Particles

STP (Standard Temperature and Pressure)

Standard conditions for gas measurements: Standard temperature is 273 K, standard pressure is 101.325 kPa (1 atm or 760 mmHg), and standard volume for one mole is 22.4 L.

Absolute Zero

The temperature of a gas at zero volume; equivalent to 0 K or -273°C.

Avogadro’s number

6.02 x 10^23 particles/atoms

Postulates of the Kinetic Molecular Theory

1. Gas particles have insignificant volume compared to the gas volume. 2. Gases consist of large numbers of particles in constant random motion. 3. Gas particles are not attracted to each other. 4. Energy is exchanged through perfectly elastic collisions. 5. Average KE is directly proportional to Kelvin temperature.

Relationship between Kinetic Energy and Temperature

Kinetic Energy and Temperature are Directly Proportional

Ideal Gases

Fictional gases used for theoretical calculations. They do not account for the volume of gas particles or interparticle attractions/repulsions, and assume perfectly elastic collisions.

Boyle's Law

For a closed system, the volume of an ideal gas is inversely proportional to the pressure of the gas, when temperature and number of particles are constant (P₁V₁ = P₂V₂).

Charles' Law

In a closed system, volume and temperature are directly proportional when pressure and the number of particles are constant (V₁/T₁ = V₂/T₂).

Gay-Lussac’s Law

The pressure of a gas of fixed mass and fixed volume is directly proportional to the absolute temperature of the gas (P₁/T₁ = P₂/T₂).

Avogadro’s Law

Equal volumes of all gases at the same temperature and pressure have the same number of molecules. As the number of moles of gas increases, the volume also increases in proportion (V₁/n₁ = V₂/n₂).

Combined Gas Law

Combines Boyle's, Charles's, and Gay-Lussac's laws: (P₁V₁)/T₁ = (P₂V₂)/T₂

Ideal Gas Equation

PV = nRT, where P is pressure, V is volume, n is the number of moles, R is the gas constant, and T is temperature in Kelvin.

Gas Constant (R)

0.08206 L atm/mol K or 8.31 kPa L / mol K