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Introduction to Organic Compounds

May 28, 2025

Some Families of Organic Compounds HL

Objectives

  • Define tetrahedral carbon
  • Explain the term alcohol
  • Describe alcohols as a homologous series
  • Explain chloroalkanes
  • Name chloroalkanes and alcohols, primary and secondary, up to C4
  • Discuss chloroalkanes as solvents
  • Draw structural formulas for chloroalkanes and alcohols up to C4
  • Account for physical properties (state, solubility) of alkanes, chloroalkanes, and alcohols up to C4
  • Discuss solubility of methanol and butan-1-ol in cyclohexane and water
  • Use of ethanol as a solvent and methanol as a denaturing agent
  • Recall fermentation as a source of ethanol
  • Discuss fermentation in brewing and distilling industries
  • Define planar carbon and carbonyl compound
  • Describe aldehydes, ketones, carboxylic acids, and esters as homologous series
  • Name and draw structural formulas for aldehydes, ketones, carboxylic acids, and esters up to C4
  • Discuss solubility of relevant compounds in cyclohexane and water
  • Recall examples and uses of various organic compounds

Key Concepts & Definitions

Tetrahedral Carbons

  • Tetrahedral carbon: A carbon with tetrahedral geometry, occurring when bonded to four single bonds.

Chloroalkanes

  • Definition: Alkanes where hydrogen atoms are replaced by chlorine atoms.
  • Uses: Industrial solvents, e.g., dry cleaning.
  • Physical Properties: Weakly polar, not soluble in water, soluble in non-polar solvents.

Alcohols

  • Functional Group: -OH, name ends in '-ol'.
  • Types:
    • Primary: OH bonded to one other carbon
    • Secondary: OH bonded to two other carbons
    • Tertiary: OH bonded to three other carbons
  • Example: Ethanol (C2H5OH)
    • Produced by fermenting glucose
    • Denatured with methanol (methylated spirits)
  • Physical Properties: Higher boiling points due to hydrogen bonding, solubility varies with molecule size.

Planar Carbons

  • Planar carbon: Carbon with planar geometry, occurring when unsaturated.

Aldehydes

  • Functional Group: -CHO, name ends in '-al'.
  • Physical Properties: Polar carbonyl group, dipole-dipole intermolecular forces, higher boiling points than alkanes.

Ketones

  • Functional Group: -CO-, name ends in '-one'.
  • Uses: Propanone in nail polish remover.
  • Physical Properties: Dipole-dipole forces, soluble in water.

Carboxylic Acids

  • Functional Group: -COOH, name ends in '-oic acid'.
  • Used as flavouring agents and preservatives.
  • Physical Properties: Hydrogen bonding intermolecular forces, high boiling points.

Esters

  • Functional Group: -COOC-, name ends in '-yl -oate'.
  • Formation: From alcohol and carboxylic acid, condensation reaction.
  • Uses: Flavourings and fragrances.
  • Physical Properties: Dipole-dipole intermolecular forces.

Aromatic Compounds

  • Structure: Contains a benzene ring.
  • Bonding in Benzene: Stable structure with equal bond lengths.
  • Examples: Many natural products contain benzene rings.

Important Notes

  • Ability to name and draw structural formulas of each type of compound is crucial.
  • Recognition of carcinogenic nature of some aromatic compounds like benzene, and non-carcinogenic like aspirin.
  • Understanding of aromatic compounds in various applications, including pharmaceuticals and industrial solvents.