Alkanes,Alkenes, and Alcohols

• What are Alkanes?

  a homologous series of similar hydrocarbons in which all the carbon atoms are joined together by single covalent bonds.
• What does saturated mean?

  Saturated means that there are carbon - carbon single bonds , there are no double bonds.
• What is the general formula of Alkanes?

  CnH2n+2
• Give 3 characteristics of a homologous series.

  - They have the same functional group

  - They have similar chemical properties

  - They can be described by the same general formula
• Tre or false. Alkanes are inert.

  True.
• What 2 reactions can alkanes undergo?

  Combustion and substitution
• When there is complete combustion of an Alkane what are the products?

  Carbon dioxide and Water.
• When there is incomplete combustion of an Alkane what are the products?

  Carbon monoxide and water.
• What condition is required for a substitution reaction?

  UV radiation.
• What do we call the products formed when alkanes react with halogens?

  Halogenoalkanes.
• What is mono substitution?


  A substitution reaction in which only one hydrogen atom in an alkane is replaced by a halogen atom.
• what is a substitution reaction?

  It is a reaction in which an atom or group of atoms in a molecule is replaced by a different atom or group of atoms.
• What are Alkenes?

  They are a homologous series of hydrocarbons which contain a carbon-carbon double bond.
• What are Alkenes used for?

  Alkenes are used to make polymers and plastics
• How do you test for unsaturated compounds?

  - Add bromine water

  - if it is unsaturated, the bromine water will change from orange to colourless
• What reactions do Alkenes undergo?

  addition and combustion reactions
• What is the general formula of Alkenes?

  CnH2n
• What is a hydration reaction?

  A hydration reaction is the addition of water molecules to an unsaturated molecule
• What are the required conditions for a hydration reaction?

  Temperature : 300 degrees Celsius

  pressure: 60-70 atmospheres

  Catalyst : Phosphoric acid
• What are alcohols?

  They are a homologous series of compounds which all contain an OH functional group attached to a hydrocarbon chain.
• what are the three ways ethanol can be oxidised?

  - Complete combustion

  - microbial oxidation

  - heating with potassium dichromate and sulfuric acid
• Describe microbial oxidation.

  Bacteria in the air uses oxygen to oxidise the ethanol and to form a weak solution of ethanoic acid.
• Describe how ethanol is oxidised using potassium dichromate.

  - Ethanol is heated with potassium dichromate in dilute sulfuric acid

  - ethanol oxidises and forms ethanoic acid and water
• During the reaction between ethanol and potassium dichromate what colour change occurs?

  Potassium dichromate changes from orange to gree.
• What is the general formula for alcohols?

  CnH2n+1OH