(adsbygoogle = window.adsbygoogle || []).push({}); [SOLVED] Rotational Kinetic Energy and distribution of diatomic molecules

a) Calculate the total rotational kinetic energy of the molecules in 1.00 mol of a diatomic gas at 300 K.

b) Calculate the moment of inertia of an oxygen molecule (O2) for rotation about either the x- or y-axis shown in the figure. Treat the molecule as two massive points (representing the oxygen atoms) separated by a distance 1.21×10-10m. The molar mass of oxygen atoms is 16 g/mol.

c) Find the rms angular velocity of rotation of an oxygen molecule about either an x- or y-axis

2. Relevant equations

kT=2/3*<k>

where, k is boltzman constant and K is kinetic energy

I=mR^2

E(rot)= 1/2*I*angular velocity(for x)^2 + 1/2*I*angular velocity(for y)^2

3. The attempt at a solution

To find the answer to the first part of the problem I used the first equation listed and got 6.21E-21 J, but that answer is incorrect. I do not know how else to approach the problem. I think it went wrong because K in that equation is the average kinetic energy and not the rotational kinetic energy, but I couldn't find another equation that would work.

For the second part I used I=mR^2. To find m, I took the molar mass and divided by avagadros number and I used the distance given for R.

my answer was: 3.89E-46 kg*m^2, but I don't think that was correct.

For the third part, I would think that you would use Vrms equals the squareroot of (3kT/m). But we are not given the temperature. So I don't know how to go about this part either.

I would really appreciate help on these three parts. Thank you!

**Physics Forums - The Fusion of Science and Community**

# Rotational Kinetic Energy and distribution of diatomic molecules

Know someone interested in this topic? Share a link to this question via email,
Google+,
Twitter, or
Facebook

Have something to add?

- Similar discussions for: Rotational Kinetic Energy and distribution of diatomic molecules

Loading...

**Physics Forums - The Fusion of Science and Community**