[Twickel]

Hi
I have a question, I was leaning towards the answer being one, however now I am not so sure because the partition function of rotational motion is given by the characterisitc temperature of rotation and this value is effected by bond length.

Consider the isomerization of a homonuclear diatomic molecule. The two isomers, A and B, differ only in the bond length which, for A and B, are 1.5 Å and 1.1 Å, respectively. What is the value of the equilibrium ratio of NB/NA?
Answer
 
a.   0.54
 
b.   1.36
 
c.   0.73
 
d.   1.00
 
e.   1.86

[Twickel]

Attached is some working to how I got the answer to be E = 1.86

please check it.