Topic 7 - Organic chemistry

• What is crude oil?

  A mixture of compounds; a fossil fuel
• What is a hydrocarbon?

  A compound made of hydrogen and carbon
• What is the general formula for alkanes?

  $C_nH_{2n+2}$
• What is a homologous series?

  Compounds with the same general formula and functional groups
• What are the products of complete combustion of hydrocarbons?

  Carbon dioxide and water
• What are the products of incomplete combustion of hydrocarbons?

  Carbon or carbon monoxide and water
• What happens to the boiling points of alkanes as the molecules get bigger?

  Boiling points increase
• How does fractional distillation of crude oil work?

  Crude oil is heated, vaporized, and separated by boiling points
• What is cracking?

  Breaking down large hydrocarbons into smaller molecules
• What type of reaction is cracking?

  Thermal decomposition
• What are the conditions for catalytic cracking?

  Heated to vapor and passed over a hot catalyst
• What are the products of cracking used for?

  Alkanes and alkenes used as polymers and starting materials
• What is the general formula for alkenes?

  $C_nH_{2n}$
• What is the test for alkenes?

  Bromine water changes from orange to colorless
• Why do alkenes burn with smoky flames?

  Due to incomplete combustion
• What happens in the addition reaction of alkenes with hydrogen?

  Hydrogenation occurs, requiring a nickel catalyst
• What functional group do alcohols contain?

  -OH
• What happens when alcohols react with sodium?

  Hydrogen gas is produced
• What is produced when alcohols are oxidized?

  Carboxylic acids
• What are the conditions required for fermentation of glucose?

  30°C, aqueous solution, absence of air, yeast
• What functional group do carboxylic acids contain?

  -COOH
• What happens when carboxylic acids react with metal carbonates?

  Carbon dioxide is produced
• Why are carboxylic acids considered weak acids?

  They are partially dissociated in water
• What is an ester?

  An organic compound with a -COO- functional group
• How are esters formed?

  From carboxylic acid and alcohol with a sulfuric acid catalyst
• What is a polymer?

  A long chain molecule made of smaller molecules
• How do molecules with C=C bonds form polymers?

  Through addition polymerization
• What is the repeating unit of a polymer?

  The smallest structure that repeats to form the polymer
• What is a condensation polymer?

  A polymer formed with the release of a small molecule
• What is an amide bond?

  A bond similar to an ester but with N instead of O
• What is an amino acid?

  An organic compound with -COOH and -NH2 groups
• How do amino acids form proteins?

  Through condensation polymerization
• What are carbohydrates?

  Organic molecules made of C, H, and O
• What is the structure of DNA?

  Two polymer chains held together in a double helix
• What are the physical properties of alkanes?

  • First few are gases, then liquids, then solids
  • Boiling points and viscosity increase with size
  • Volatility and flammability decrease with size
  • Poor reactivity
• What are the characteristics of methanol, ethanol, propanol, and butanol?

  • Dissolve in water to form neutral solutions
  • React with sodium to form hydrogen
  • Burn in oxygen
  • React with carboxylic acids to form esters
• What are the characteristics of carboxylic acids?

  • Form acidic solutions in water
  • React with metal carbonates to produce CO2
  • React with alcohols to form esters
  • React with metals to produce hydrogen
• What are the uses of alcohols?

  • Fuels
  • Solvents
  • Drinks
• What are the examples of addition polymers and their uses?

  • Polyethene: plastic bags
  • PTFE: non-stick kitchenware
  • PVC: water pipes
• What are the steps in fractional distillation of crude oil?

  1. Crude oil is heated and vaporized
  2. Vapor rises up the fractionating column
  3. Hydrocarbons condense at different heights based on boiling points
  4. Large molecules collected at the bottom, small molecules at the top