Chem 335 - Winter 1999 -
Organic Chemistry II (1 point each)
1. In infrared spectroscopy, wavenumber is typically expressed in units of
a) micrometers
b) cm
c) nm
d) cm-1
e) no units
2. Molecular nitrogen ( N2 ) does not absorb infrared light because
a) it's nonpolar
b) it's a gas
c) it only has one kind of bond
d) its vibrational energy is out of the IR range
e) it's a linear molecule
3. All else being equal, a bond to a heavier atom (e.g., C-D compared to C-H) will show an IR absorption
a) at a lower frequency and lower wavenumber
b) at a lower frequency and higher wavenumber
c) at a higher frequency and lower wavenumber
d) at a higher frequency and higher wavenumber
e) at an identical frequency and wavenumber
4. The fingerprint region is called that because the peaks are usually
a) finely spaced
b) broad
c) characteristic
d) unidentifiable
e) smudged
5. According to the Beer-Lambert law, if a cuvette of a solution absorbs half of the incident light intensity, adding a second identical cuvette behind the first one will further reduce the intensity (compared to the original intensity as 100%)
a) to zero
b) to 50%
c) to 25%
d) to 10%
e) to some other value