Kinetic molecular theory

kinetic molecular theory

Kinetic molecular theory states that the tiny particles in all forms are in constant motion

postulate one

gases are made of tiny particles far apart relative to their size

• explains why gases are compressible

postulate two

gas particles are in constant, random motion

• as a result, there are collisions with other molecules or with the wall of the container

• wall collisions create pressure

postulate three

gas particles do not attract or repel each other

postulate four

gas particles have elastic collisions, meaning they do not lose kinetic energy when they collide

postulate five

gas particles’ kinetic energy depends on their temperature

• all gases at the same temperature have the same average kinetic energy

characteristics of gases

• gases expand to fill any container

• gases are fluids (like liquids)

• gases have very low densities

• gases can be compressed

• gases undergo diffusion and effusion

ideal vs. real gases

• ideal gases follow the assumptions of the kinetic molecular theory

• real gases

  (have their own volume)

(attract each other)

• gas behavior is most ideal

(at low pressures)

(at high temperatures)

(in non polar atoms/molecules)

Dalton’s Law of Partial Pressure

Ptotal= P1+P2+P…..