ORGANIC ANALISYS

• Tests for Functional Groups:

  • Alcohols:
  • 1​o​ and 2​o​ alcohols are identified using acidified potassium dichromate, turning from orange to green if present
  • 3​o​ alcohols are not oxidised, and the potassium dichromate remains orange
  • Aldehydes:
  • Tollen’s reagent forms a silver mirror in the presence of aldehydes
  • Fehling's solution forms a brick red precipitate if an aldehyde is present
  • Alkenes:
  • Bromine water changes from orange-brown to colorless in the presence of a carbon-carbon double bond
  • Carboxylic Acid:
  • React with sodium carbonate as acids, producing CO​2​, which turns limewater cloudy
• Mass Spectrometry is used to identify compounds and determine their molecular formula
• High Resolution Mass Spectrometry is a more sensitive form that allows the Mr of a substance to be determined to several decimal places
• Infrared Spectroscopy uses infrared radiation to determine the functional groups present in organic compounds
• Infrared absorption in the atmosphere, like with ozone, traps heat within the Earth’s atmosphere, contributing to global warming