Organic analysis

• Alcohols: primary and secondary alcohols can be identified using acidified potassium dichromate, which changes from orange to green in their presence, while tertiary alcohols do not oxidize and the potassium dichromate remains orange.
• Aldehydes: Tollen's reagent can be used to identify aldehydes, where a silver mirror forms in the test tube if an aldehyde is present, and Fehling's solution can also be used, where a brick red precipitate forms in the presence of an aldehyde.
• Alkenes: Bromine water is used to test for unsaturated hydrocarbons, changing from orange-brown to colorless if a carbon-carbon double bond is present.
• Carboxylic Acid: These compounds react with sodium carbonate as acids, producing CO2, which can be tested using limewater that turns cloudy in the presence of CO2.
• Mass Spectrometry: An analytical technique used to identify compounds and determine their molecular formula, with high resolution mass spectrometry being more sensitive and allowing for precise determination of the Mr and molecular formula.
• Infrared Spectroscopy: An analytical technique that uses infrared radiation to determine the functional groups present in organic compounds, with characteristic peaks for different functional groups such as -OH alcohol group, -OH acid group, C=C unsaturated group, and C=O carbonyl group.
• Each IR spectrum has a fingerprint region that contains tiny differences from species to species, allowing for identification of specific molecules.
• High resolution mass spectroscopy can measure the mass to 5 d.p. This can help differentiate between compounds that appear to have similar Mr (to the nearest whole number)