kinetics theory
there is a distribution of speeds of particles in the gases in any given vessel
to measure the speed of a gas particle, use a set of spinning discs with a detector
root mean square speed (vrms)
considers the pressure the gas exerts ie by colliding with the walls of the vessels
mean speed (Vmean)
average kinetic energy of the partiles
kinetic energy in any particle is = 1/2mv^2
total kinetic energy of an ideal gas = Ek=3/2nRT
Maxwell distribution (v/ms-1) (speed)
where we know the molar mass of the particles (real gases) to determine the velocity of the particles
2 samples of the same gas @ the same temp will have the same distribution of speeds regardless of volume/ vessel type
average speed of particles in the vessel
assymetric shape, Vmp at peak, them Mean, Vms (think alphabetical, e goes before s)
amp (most probable speed)
largest number of molecules travelling at this speed
increase in temp- more kinetic energy so Vmp increases
particles with lower mass will have a wider distribution as lighter gasses are more likely to travel at a higher speed
Boltzmann dsibtribution (kinetic energy)
ideal gases-particle mass has no effect on kinetic energy distribution for Boltzmann which looks at energy, instead of velocity.
all collisions are elastic so the total kinetic energy remains the same
how much energy can be involved when 2 particles collide and thus is they are able to overcome the activation energy
number of collisions with energy equal to or above the activation energy = exp(-Ea/RT)
averages go Emp, Emean
temp has a greater effect on kinetic energy than on speed as it has a linear dependance.