4.2.4 - Analytical Techniques

• What is the purpose of elemental analysis?

  To determine the proportion of elements in a compound
• How is elemental analysis performed on an unknown sample?

  By converting it into simple known compounds
• What happens during fragmentation in mass spectrometry?

  Unstable molecular ions break down into smaller fragments
• What are fragment ions?

  Smaller ions formed from unstable molecular ions
• What is infrared radiation absorbed by in molecules?

  Covalent bonds, causing them to vibrate
• What is the purpose of infrared spectroscopy?

  To identify bonds and functional groups in molecules
• How has infrared spectroscopy been linked to global warming?

  • Monitors atmospheric gases
  • Identifies C=O, O-H, C-H bonds
  • Shows distinct peaks on IR spectra
• What gases causing air pollution are monitored by infrared spectroscopy?

  CO and NO from car emissions
• What is the M+1 peak in mass spectrometry?

  A small peak caused by carbon-13 presence
• What does the MZ ratio represent in mass spectrometry?

  The mass to charge ratio of an ion
• What is mass spectrometry used for?

  To identify compounds and determine molecular mass
• What is the molecular ion peak in mass spectrometry?

  The peak with the highest m/z value
• How is molecular mass defined?

  The total number of atoms of each element