Worksheet: Functional Groups in UV–Vis Spectra

In this worksheet, we will practice identifying functional groups in a compound by assessing the shapes and positions of peaks in UV–Vis spectra.


The method of continuous variations, also known as Job’s method, uses the intersection of the ligand line and the metal line to determine .

  • Athe maximum intensity of source photons transmitted
  • Bthe oxidation number of the metal
  • Cthe concentration at which the detector can no longer respond to the signal
  • Dthe mole ratio between the metal and ligand in a complex
  • Ethe number of dimeric molecules formed


Which of the following would result in a hypsochromic shift in the UV spectrum?

  • ADehydration of an alcohol to form a double bond
  • BAddition of an amino group
  • CSaturation of a double bond
  • DCyclization of an aliphatic compound


What does increasing conjugation in a series of analogous compounds result in?

  • AHypochromic effect
  • BBathochromic shift
  • CHyperchromic effect
  • DHypsochromic shift


Why does increased conjugation cause a shift to higher wavelengths?

  • AIt decreases the distance (Δ𝐸) between the HOMO and LUMO levels.
  • BIt increases the distance (Δ𝐸) between the HOMO and LUMO levels.
  • CIt changes the types of electronic transitions available from 𝜋𝜋- to 𝑛𝜋-.
  • DIt causes the vibrational and rotational levels of the molecules to become excited.


Which of the following is true of the Woodward–Fieser rules for conjugated carbonyl compounds?

  • AThey can also be applied to benzene derivatives.
  • BThey only include substitutes directly adjacent to the carbonyl group.
  • CThey are the same as the rules for dienes.
  • DThey include a solvent correction value.


In general, when calculating empirical values for 𝜆max, what is the result of adding a substituent group?

  • AA hypochromic effect
  • BA hypsochromic shift
  • CA hyperchromic effect
  • DA bathochromic shift

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