In: Chemistry
1. Determine the ratio of populations in the lowest and first excited energy levels, Po/P1, for the indicated systems at two temperatures, 50 K and 298 K: a) The 1700 cm−1 stretching mode for the carbonyl group in the peptide bond of a polypeptide b) the 150 cm−1 torsional mode for the C=C bond in trans-2-butadiene
Ans :
a) Here wavenumber = 1700cm-1
speed of light = 2.9x1010 cm/s
Now harmonic frequency = (2.9x1010 cm/s)(1700 cm-1)
=4.93x1013 /sec
At 50 K , the population ratio
Population ratio at 298K
b) Here wavenumber = 150cm-1
speed of light = 2.9x1010 cm/s
Now, harmonic frequency =(2.9x1010 cm/s)(150 /cm)
=4.35x1012 /sec
At 50K , the population ratio
At 298K , the population ratio