P3.3 - Kinetic Theory

What are the assumptions of kinetic theory?

• Volume of molecules is negligible compared to the size of the gas

• Time between collisions is much longer than during

• Collision between molecules are elastic

• Forces of attraction between molecules are negligible

• Gases consist a large number of molecules in rapid, random motion

What is an ideal gas?

A gas which strictly obeys the equation of state. With the exception of very high densities, a real gas approximates well to an ideal gas

What is ideal gas equation?

pV=nRT

pV=NkT

What are the 3 gas laws?

• Pressure is inversely proportional to volume at constant T

• Pressure is directly proportional to Temp at constant volume

• Volume is directly proportional to T at constant pressure

What are the conditions for an ideal gas?

T and P aren’t too extreme

What are the assumptions of an ideal gas?

• Collide with no loss of KE

• Only exert forces on each other during collisions

• Molecules are assumed to take up no space

What is the equation for the Boltzmann constant?

k=R/NA

What are the equations for moles?

n=N/NA

n=m/Mr

What is a mole?

The SI unit of an amount of substance. Amount containing as many particles as there are atoms in 12g of carbon-12

What is the avogadro constant?

Number of particles per mole

What is the equation for pressure exerted by a gas?

Why is mean squared speed used when calculating pressure?

Energy of the particles is distributed randomly. This is a way of representing the speed squared of an average molecule

What is relative molecular mass?

Mr

Mass of a molecule relative to the mass of Carbon-12

What is molar mass?

M

Mass of 1 mole of a substance

What is the equation for Molar Mass?

M/kg = Mr/1000

What causes the pressure exerted by a gas?

Molecular movement

What is the equation for total translational Kinetic Energy?

Total tKE= 3/2RT

What is the equation for the mean Kinetic Energy of a molecule?

Mean KE of a molecule = 3/2kT

What is the derivation for the equation for total translational kinetic energy?

What is the derivation for the equation for the mean KE of a molecule?

What are the 3 fundamental gas laws?

pV = constant

V/T = constant

p/T = constant

In the 3 fundamental gas laws, what is the value of the constant dependent on?

Mass of the gas

How do you calculate root mean square speed?

Add the square of the speeds, divide by the number of speeds. Square root

The equation pV=nRT works for many real gases as long as what?

The temperature and pressure of the gases aren’t too extreme