How to Calculate Bond Strength in a Molecule?

solas99
Messages
69
Reaction score
1

Homework Statement


Carbon monoxide molecule, which has a reduced mass of 6.85 amu, absorbs infrared radiation wavelength of 4.6um. if the absorption is due to vibrational transitions, calculate the strength of the bond in molecule


Homework Equations



u=(m1*m2)/(m1+m2)

The Attempt at a Solution



1. (12*16)/(12+16)=6.85 amu= 1.13e-26 Kg


here i calculate the reduced mass...but the reduced mass is given in the question! i just don't know what equation to use to calculate bond strength from wavelength and reduced mass..

there is another equation for frequency of vibrations: v=1/2pi \sqrt{k/u}

but i don't know what k stands for? and how we calculate it
is there any other equation I am missing?

thank you!
 
Last edited:
Physics news on Phys.org
k is called the force constant of stretching the bond between carbon and oxygen, and it characterises the stiffness of this bond. Search your notes what was called "the strength of the bond". You can calculate k from the given data. Remember that a vibrating molecule absorbs that radiation which frequency corresponds its vibrational frequency. ehild
 
E=h(n+1/2)w
 
is k the bond strength?

from equation λ=2pic\sqrt{u/k}

do we then solve for K, to give the bond strength?

thanks a mill :)
 
Well, k is not the bond strength, but your book might call it so. Anyway, calculate it.

ehild
 
##|\Psi|^2=\frac{1}{\sqrt{\pi b^2}}\exp(\frac{-(x-x_0)^2}{b^2}).## ##\braket{x}=\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dx\,x\exp(-\frac{(x-x_0)^2}{b^2}).## ##y=x-x_0 \quad x=y+x_0 \quad dy=dx.## The boundaries remain infinite, I believe. ##\frac{1}{\sqrt{\pi b^2}}\int_{-\infty}^{\infty}dy(y+x_0)\exp(\frac{-y^2}{b^2}).## ##\frac{2}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,y\exp(\frac{-y^2}{b^2})+\frac{2x_0}{\sqrt{\pi b^2}}\int_0^{\infty}dy\,\exp(-\frac{y^2}{b^2}).## I then resolved the two...
Hello everyone, I’m considering a point charge q that oscillates harmonically about the origin along the z-axis, e.g. $$z_{q}(t)= A\sin(wt)$$ In a strongly simplified / quasi-instantaneous approximation I ignore retardation and take the electric field at the position ##r=(x,y,z)## simply to be the “Coulomb field at the charge’s instantaneous position”: $$E(r,t)=\frac{q}{4\pi\varepsilon_{0}}\frac{r-r_{q}(t)}{||r-r_{q}(t)||^{3}}$$ with $$r_{q}(t)=(0,0,z_{q}(t))$$ (I’m aware this isn’t...
Hi, I had an exam and I completely messed up a problem. Especially one part which was necessary for the rest of the problem. Basically, I have a wormhole metric: $$(ds)^2 = -(dt)^2 + (dr)^2 + (r^2 + b^2)( (d\theta)^2 + sin^2 \theta (d\phi)^2 )$$ Where ##b=1## with an orbit only in the equatorial plane. We also know from the question that the orbit must satisfy this relationship: $$\varepsilon = \frac{1}{2} (\frac{dr}{d\tau})^2 + V_{eff}(r)$$ Ultimately, I was tasked to find the initial...
Back
Top