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### H.W. Problem 1.55

Posted: Sun Oct 02, 2016 4:52 pm
Infrared spectroscopy is an important tool for studying vibrations of molecules. Just as an atom can absorb a photon of suitable energy to move an electron from one electronic state to another, a molecule can absorb a photon of electromagnetic radiation in the infrared region to move from one vibrational energy level to another. In infrared spectroscopy, it is common to express energy in terms of /c, with the units cm 1 (read as reciprocal centimeters).

(a) If an absorption occurs in the infrared spectrum at 3600 cm^-1, what is the frequency of radiation that corresponds to that absorption? (b) What is the energy, in joules (J), of that absorption? (c) How much energy would be absorbed by 1.00 mol of molecules absorbing at 3600 cm^-1?

How do we use DeBroglie's Equation with units such as cm^-1? How can we change the units to m without the negative exponent?

### Re: H.W. Problem 1.55

Posted: Sun Oct 02, 2016 11:08 pm
I am confused because this is not a de Broglie question.

### Re: H.W. Problem 1.55

Posted: Tue Oct 16, 2018 5:19 pm
Why do we have to multiply 3600 by 100. I get that 100 cm is a meter, but wouldn't we then divide 3600 to get 3.6 meters?

### Re: H.W. Problem 1.55

Posted: Thu Oct 18, 2018 2:36 pm
I think they are multiplying by 100cm/m to convert the speed of light from m/s to cm/s. That is how I interpreted the answer.