 ## CuriousTab ## Spectroscopy problems

• 1. In the equation, A = ? bc, what quantity is represented by "?"?

• Options
• A. Absorbtivity
• B. Molar absorbtivity
• C. Path length
• D. None of these
• 2. Why are rotational transitions of little use to a spectroscopist?

• Options
• A. Because the energy required to induce a rotational transition is so small that it cannot be measured
• B. Because rotational transitions are extremely rare
• C. Because, in liquids and solids, spectral lines corresponding to rotational transitions are broadened as the result of molecular collisions and other interactions
• D. All of the above
• 3. Why is it generally preferable to use absorbance as a measure of absorption rather than % transmittance?

• Options
• A. Because %T cannot be measured as accurately as absorbance
• B. Because %T is dependant on the power of the incident radiation
• C. Because absorbance is proportional to the concentration of the analyte, whereas %T is not
• D. none of the above
• 4. A simple harmonic oscillator may absorb energy

• Options
• A. at anytime.
• B. when the frequencies match exactly
• C. when the amplitudes are the same.
• D. at no time.
• 5. Beer's Law states that

• Options
• A. absorbance is proportional to both the path length and concentration of the absorbing species
• B. absorbance is proportional to the log of the concentration of the absorbing species
• C. absorbance is equal to P0 / P
• D. none of the above
• 6. Vibrational spectroscopy is

• Options
• A. a large mass on a weak spring
• B. a flashlight through a prism and shake it
• C. a class of spectroscopic techniques which analyzes molecular motions
• D. an Infrared spectroscopy
• 7. Molar absorbtivity is the measure of the

• Options
• A. amount of light absorbed per unit length
• B. amount of light absorbed per unit concentration
• C. amount of light reflected and absorbed per unit concentration
• D. None of the above
• 8. Molar absorbtivities of compounds exhibiting charge transfer absorption are

• Options
• A. small
• B. moderate
• C. large
• D. none of these
• 9. In the past, IR spectra had to be aquired one wavelength at a time, which took a long time. Today quick spectra is due to the

• Options
• A. the Fourier Transfer Algorithm allows us to scan all frequencies at once
• B. light is faster today that it used to be
• C. absence of broad spectrum of wavelenth
• D. none of the above
• 10. UV-Vis spectroscopy of organic compounds is usually concerned with which electronic transition(s)?

• Options
• A. ? ? ?*
• B. n ? ?*
• C. n ? ?* and ? ? ?*
• D. none of these