Organic analysis revision notes

Organic Analysis Techniques

Organic analysis involves various methods to identify and characterize organic compounds. Key techniques include:

1. Test-Tube Reactions

• Alcohols: React with potassium dichromate to produce a color change from orange to green.
• Aldehydes: Use Tollen's reagent to form a silver mirror.
• Alkenes: Test with bromine water; a color change from brown to colorless indicates the presence of an alkene.
• Carboxylic Acids: React with sodium bicarbonate to produce carbon dioxide gas, observed as bubbling.

2. Mass Spectrometry

• Analyze the mass spectrum to identify the molecular ion peak, which corresponds to the molecular weight of the compound.
• Fragmentation patterns provide insights into the structure of the molecule, aiding in identification.

3. Infrared Spectroscopy

• Identify functional groups by analyzing the absorption peaks in the IR spectrum.
• The fingerprint region (below 1500 cm⁻¹) is unique for each compound and can be compared with reference spectra for identification.
• Infrared spectroscopy can also monitor atmospheric gases like CO₂, CH₄, and H₂O by detecting their characteristic absorption bands.