1. The problem statement, all variables and given/known data Experimental data for the heat capacity of N2 as a function of temperature are provided. Estimate the frequency of vibration of the N2 molecule. 2. Relevant equations Energy of harmonic oscillator = (n+1/2)ħω C=7/2kB Average molecular energy = C*T But this is an expression for the total energy of a molecule. Presumably the amount of energy within the two vibrational modes is: E=C*T with C=kB 3. The attempt at a solution All I can think to do is equate the two expressions for the energy of the oscillator: kBT=(n+1/2)ħω But I have no idea where to go now. In order to find frequency I would want to solve for ω, from which frequency can be trivially determined. However, how am I to know which integer value to use for n? I am also very unsure as to my construction of the problem. Any help/guidance greatly appreciated.