Chemistry How Accurate Is the Calculated Spring Constant of a Diatomic Molecule?

AI Thread Summary
The calculated spring constant for the diatomic molecule is 9.18 x 10^-6 kg/s^2, which seems unexpectedly low compared to typical values of 400-800 N/m for bond forces. The user derived this value using the relation between angular frequency and spring constant, but questions arise regarding the conversion from frequency to wavenumber and the value of 'c' used in the calculations. Clarifications are sought on the experimental measurement of frequency and the reasoning behind the wavenumber output. The discussion highlights potential misunderstandings in the calculations and the need for accurate conversion methods. Accurate determination of the spring constant is crucial for understanding molecular bond strength.
greisen
Messages
75
Reaction score
0
Hi,
I have to determine the spring constant for a diatomic molecule. I have the frequency in cm^-1 which is 1395.
I know the relation between the angular frequency and spring constant so I use the following relation:
omega = 2*pi*c*v = sqrt(k/mu)

so I isolate for k = mu*(2*pi*c*v)^2

mu = 8*1.66*10^-27
v = 1395 cm^-1

which gives me k = 9.18*10^-6 kg/s^2

This strikes me as a rather strange result? For a diatomic molecule I would expect something like at least 400-800 N/m for the bond force? What is wrong ? Thanks in advance.
 
Physics news on Phys.org
I'm not sure how exactly you go from frequency to wavenumber (or viceversa). It looks like you've used a linear dispersion with some value of c. What value did you use? Where did you get this from? Experimentally, how is the frequency measured (and why is the output in the form of a wavenumber)?
 
Thread 'Confusion regarding a chemical kinetics problem'
TL;DR Summary: cannot find out error in solution proposed. [![question with rate laws][1]][1] Now the rate law for the reaction (i.e reaction rate) can be written as: $$ R= k[N_2O_5] $$ my main question is, WHAT is this reaction equal to? what I mean here is, whether $$k[N_2O_5]= -d[N_2O_5]/dt$$ or is it $$k[N_2O_5]= -1/2 \frac{d}{dt} [N_2O_5] $$ ? The latter seems to be more apt, as the reaction rate must be -1/2 (disappearance rate of N2O5), which adheres to the stoichiometry of the...
Back
Top