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Topic: IR Spectrum help  (Read 3496 times)

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Offline thao.l.dang

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IR Spectrum help
« on: April 02, 2013, 07:42:12 PM »
I have an IR spectrum of an unknown compound. In order to identify the functional groups, I'm referencing a document given by my university, but the units are in cm-1. My IR is taken in ppm and Hz, and I am converting to find the wavenumber but end up getting a very small number.

ie. peak = 322.8 Hz
wavenumber = 1/λ = ν/c
322.8/3.0 x 10^10
= a very very small number.

the areas of interest are in the thousands cm-1

Please tell me what I'm doing wrong and how I can interpret this IR spectrum from Hz.
Thanks! much appreciated!

Offline Corribus

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Re: IR Spectrum help
« Reply #1 on: April 02, 2013, 07:56:38 PM »
Are you sure the units are Hz?  Even radio waves are in the thousands of Hz.  IR light is 1012 - 1014 Hz or thereabout.

Look here:

http://en.wikipedia.org/wiki/File:EM_Spectrum_Properties_edit.svg
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

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