organic chemistry

• What is crude oil?

  A mixture of compounds from ancient biomass
• Why is crude oil considered a finite resource?

  It cannot be replaced as it is used up
• What is a hydrocarbon?

  A compound of hydrogen and carbon atoms
• What are alkanes?

  Saturated hydrocarbons with formula CnH2n+2
• What defines a homologous series?

  Compounds with same formula and properties
• Describe the combustion of hydrocarbons.

  • Exothermic reaction with oxygen
  • Complete combustion: produces CO2 and water
  • Incomplete combustion: produces carbon or CO and water
• Describe 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
  • Generally poor reactivity
• What is cracking?

  Thermal breakdown of large hydrocarbons
• What type of reaction is cracking?

  Thermal decomposition
• What are the conditions for cracking?

  Heated vapor over a catalyst or steam
• Explain how fractional distillation of crude oil takes place.

  • Crude oil is heated and vaporised
  • Vapor rises in a fractionating column
  • Column is hotter at the bottom, cooler at the top
  • Hydrocarbons condense at different heights
  • Large molecules collected at the bottom
  • Small molecules collected at the top
• How are the products of cracking used?

  • Alkanes and alkenes produced
  • Used as polymers
  • Serve as starting materials for synthesis
• What is an alkene?

  Unsaturated hydrocarbon with a C=C bond
• What is the general formula for alkenes?

  CnH2n
• What is the test for alkenes?

  Add bromine water; color changes to colorless
• Describe the combustion of alkenes.

  They burn with smoky flames due to incomplete combustion
• Describe addition reactions of alkenes.

  • Atoms added across the C=C bond
  • Hydrogenation: requires nickel catalyst and heat
  • Hydration: requires high temperature, pressure, and H3PO4
  • Addition of halogens: Br2/Cl2/I2
• What is an alcohol?

  Organic compound with an -OH functional group
• State characteristics of methanol, ethanol, propanol, and butanol.

  • Dissolve in water to form neutral solutions
  • React with sodium to produce hydrogen
  • Burn in oxygen
  • React with carboxylic acids to form esters
• What does oxidation of alcohols lead to?

  Carboxylic acids
• What are some uses of alcohols?

  • Fuels
  • Solvents
  • Drinks
• State the conditions required for fermentation of glucose and the equation of the reaction.

  • 30 degrees Celsius
  • Aqueous glucose solution
  • Absence of air
  • Yeast added
  • Equation: C6H12O6 → 2 CH3CH2OH + 2 CO2
• What are carboxylic acids?

  Organic compounds with a COOH functional group
• State characteristics of carboxylic acids.

  • Dissolve in water to form acidic solutions
  • Contain H+ ions
  • React with metals
• What are the conditions required for fermentation of glucose?

  30 degrees Celsius, aqueous glucose, absence of air, yeast
• What is the equation for the fermentation of glucose?

  C$_6$H$_{12}$O$_6$ → 2 CH$_3$CH$_2$OH + 2 CO$_2$
• What are carboxylic acids?

  Organic compounds containing a COOH functional group
• What are the characteristics of carboxylic acids?

  • Dissolve in water to form acidic solution
  • React with metal carbonates to form CO$_2$
  • React with alcohols to produce esters
  • React with metals to release hydrogen gas
• What type of acid is a carboxylic acid?

  It is a weak acid
• Why are carboxylic acids considered weak acids?

  They are partially dissociated in water
• What is an ester and how is it formed?

  An organic compound with a -COO- group, formed from carboxylic acid and alcohol
• What is characteristic about esters?

  They have a fruity smell
• What is a polymer?

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

  C=C bonds open up and join smaller molecules
• What is the process called when forming addition polymers?

  It is called addition polymerisation
• What is a repeating unit of a polymer?

  Smallest structure yielding the polymer's structure
• How do you draw the repeating unit of an addition polymer?

  Change C=C to C-C and show additional bonds
• What is a condensation polymer?

  A polymer made in condensation polymerisation
• What happens during condensation polymerisation?

  Molecules join and release a small molecule
• What is an amide bond?

  Similar to an ester bond, with O replaced by N