Kinetic Theory Of Gases Flashcards
What does the Kinetic Theory of Gases link?
Links the microscopic & macroscopic properties of particles
What are the assumptions of the Kinetic Theory of Gases?
-Molecules of a gas behave as identical (all have the same mass)
-Molecules are perfectly elastic spheres
-Volume of molecules is negligible compared to the container’s
-Time of collisions is negligible compared to the time in between
-No intermolecular forces between molecules except during impact
-Molecules move in continuous random motion
-Newton’s laws apply
-There is a large number of molecules
What causes pressure in a gas?
The collisions of the gas particles with the container’s walls
What happens to a particle during a collision?
Undergoes a change of momentum
What is the equation for change of momentum during a collision?
Δp = -mv - mv = -2mv
What does the root mean square speed relate to?
Average speed of gas particles
What is the unit for root mean square speed?
ms^-1
What is the Kinetic Theory of Gases Equation?
pV= 1/3 Nm x (mean square speed)
where p is pressure, V is volume, N is the no. Of molecules and m is the mass of one molecule of gas.
What is Boltzmann’s constant?
1.38 x 10^-23 JK^-1
What is the Average Kinetic Energy of a Molecule equation derivation?
Equate; pV = NkT ad pV = 1/3 Nm(mean square speed)
You get: 1/3 m(mss) = kT
Since E=1/2mv^2
You get; 2E= m(mss) = 3kT
Then you get;
E= (3/2)kT
Since E is directly proportional to T and k=R/NA
E also = (3RT)/2NA
What is the internal energy of an ideal gas assumptions?
All internal energy is due to kinetic energy since there are no electrostatic forces in between molecules.
What is the change in internal energy of an ideal gas?
ΔU = total kinetic energy
What’s the Kinetic Theory of Gases equation involving density?
p= 1/3 ρ x (mean square speed)
What’s the Boltzmann constant equation?
k = R/NA
Where k is the Boltzmann constant, R is the molar gas constant and NA is avagadro’s constant.
Average kinetic energy of a molecule equation.
E=(3/2)kT
Where k is Boltzmann constant and T is temperature.
Equation for Internal energy of an ideal gas.
Ek = (3/2)Nk ΔT
What’s the equation for Internal Energy of an Ideal gas involving mss?
Ek = (1/2)Nm(mss)
