Pa III (Pr) CA II

5 Questions | Total Attempts: 62

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Pa III (Pr) CA II

Uv Visible Spectroscopy


Questions and Answers
  • 1. 
    Beer’s Law (or the Beer-Lambert Law) is . . .
    • A. 

      A linear relationship between the intensity of a UV absorbance and the concentration of the analyte.

    • B. 

      An inverse relationship between the IR stretching frequency and the energy of light.

    • C. 

      An inverse relationship between the IR stretching frequency and the energy of light.

    • D. 

      Used to derive a molecular formula from the mass-to-charge ratio of an analyte.

  • 2. 
    Which of the following wavelength ranges is associated with UV spectroscopy?
    • A. 

      0.8 - 500µm

    • B. 

      400 - 100nm

    • C. 

      380 - 750nm

    • D. 

      0.01 - 10nm

  • 3. 
    Which of the following compounds does not absorb light in the UV/visible spectrum?
    • A. 

      Aspirin

    • B. 

      Paracetamol

    • C. 

      Chloral hydrate

    • D. 

      Phenobarbitone

  • 4. 
    In UV absorption spectroscopy, which of the following statements are true?
    • A. 

      σ→σ* transitions are lower in energy than π→π* transitions

    • B. 

      A conjugated systems of double bonds in a molecular shifts the a absorption maxima to higher wavelengths

    • C. 

      σ→σ* transitions are higher in energy than π→π* transitions

    • D. 

      B and C

  • 5. 
    A compound X is characterized in its electronic spectrum by an absorption with λmax = 217 nm (εmax = 21 000 dm3 mol–1 cm–1). Of the compounds given below, X is most likely to be:
    • A. 

      Buta-1,3-diene

    • B. 

      β-carotene.

    • C. 

      Ethanol.

    • D. 

      Water.

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