Ideal Gases Flashcards
What assumptions are made in the kinetic model for an ideal gas?
- gas has large number of atoms/ molecules moving randomly
- volume of gas atoms is negligible compared with the volume of the gas in the container
- atoms collide elastically with each other and the walls
- time of collisions of atoms is negligible compared with the time between the collisions
- electrostatic forced between atoms are negligible except during collisions
What is the SI base unit for amount of substance?
mole
What is Avogadro’s constant?
number of particles in a mole
Define the mole:
amount of substance that contains aqs many elementary entries as there are atoms in 0.012kg of carbon-12
How do you calculate the number of atoms and molecules in a substance?
n x avogadro’s constant (Na)
What gas law applies with pressure?
a gas of mass (m) travelling at speed (u) collifes with the container wall and bounces back with the same speed u
What is Boyle’s law?
pressure exerted by a fixed amount of gas is inversely proportional to its volume provided temperature remains constant
What was shown to be proportional after experiments on ideal gases?
- pressure and temperature (at constant volume)
- volume and temperature (at constant pressure)
What equation can pressure volume and temperature combine to give?
(p x v)/T = constant
What is the equation of state?
pV = nRt
What is an ideal gas?
- gas molecules don’t interact with each other
- molecules thought to be perfect spheres
Use kinetic theory of gases to explain why temperature increase leads to an increase in pressure:
- particles gain kinetic energy
- greater momentum
- more collisions
- change in momentum proportional to force
What does the area under a Maxwell-Boltzmann curve represent?
total number of particles
How does the MB curve change if temperature increases?
- shifts right
- lower and more spread out
What is the average kinetic energy of a particle in an ideal gas?
- 1.5kT
