Question

Which of the following statements about the ordinary IR spectroscopic regions are TRUE?

T/F In general, radio frequencies are higher wavenumbers than IR radiation.

T/F Ordinarily we are unable to see any of the frequencies in the FUNDAMENTAL region of the IR.

T/F Ordinarily we sense most IR frequencies as colors in the region we call yellow.

T/F In general, the IR FUNDAMENTAL region has a longer wavelength region than the region we call the ultraviolet (uv) region.

T/F An IR wavelength of 40 microns corresponds to a wavenumber of 25 inverse cm

Answer 1

1) F (frequency of radio wave<IR and frequency is proportional to wave no.)

2) T, R spectra involved vibrational-rotational spectra and it is very complex to identify any particular frequency instead we just study the region of frequency.

3) F ( It is called infrared because it is beyond the red, that is, outside the visible range)

4) T (frequency of IR<UV and frequency is inversely proportional to wavelength)

5) F (wavelength = 40 microns = 4 x 10^-5 m =4 x 10^-3 cm ; wave number = 1/wavelength =1/(4 x 10^-3 )=250 cm^-1 )