Holologous series (get the grade)

• What is a homologous series?

  A group of molecules with similar properties
• What groups are included in National 5 Chemistry's homologous series?

  Alkanes, alkenes, cycloalkanes, alcohols, carboxylic acids
• What is a hydrocarbon?

  A molecule containing hydrogen and carbon
• How does the name of a hydrocarbon depend on its structure?

  It depends on the number of carbons and functional groups
• What is the prefix for one carbon atom in hydrocarbons?

  Meth
• What is the prefix for two carbon atoms in hydrocarbons?

  Eth
• What is the prefix for three carbon atoms in hydrocarbons?

  Prop
• What is the prefix for four carbon atoms in hydrocarbons?

  But
• What is the prefix for five carbon atoms in hydrocarbons?

  Pent
• What is the prefix for six carbon atoms in hydrocarbons?

  Hex
• What is the prefix for seven carbon atoms in hydrocarbons?

  Hept
• What is the prefix for eight carbon atoms in hydrocarbons?

  Oct
• What are alkanes characterized by?

  Single bonds between carbon and hydrogen
• What do the names of alkanes end with?

  -ane
• What is the chemical formula for alkanes?

  C_nH_2n+2
• What are branched alkanes?

  Alkanes with branches in their structure
• How do you name branched alkanes?

  Name branches from the closest side
• What distinguishes alkenes from alkanes?

  Alkenes have a carbon-to-carbon double bond
• What does it mean for alkenes to be unsaturated?

  They contain a carbon-to-carbon double bond
• What can unsaturated molecules undergo?

  Addition reactions
• What is the chemical formula for alkenes?

  C_nH_2n
• What are cycloalkanes?

  A homologous series with a cyclic structure
• What are cycloalkanes in relation to alkenes?

  They are isomers of alkenes
• What are isomers?

  Chemicals with the same formula but different structures
• What are addition reactions?

  Reactions where a double bond adds onto another molecule
• How can you test if a molecule is unsaturated?

  Using bromine solution to check for decolourisation
• What indicates that a substance is unsaturated when using bromine solution?

  Decolourisation of the bromine solution
• What are the key points about homologous series?

  • Group of molecules with similar properties
  • Naming based on number of carbon atoms:
  • 1 = Meth
  • 2 = Eth
  • 3 = Prop
  • 4 = But
  • 5 = Pent
  • 6 = Hex
  • 7 = Hept
  • 8 = Oct
• What are the key points about alkanes?

  • Names end in -ane
  • Used for fuels
  • Chemical formula: C_nH_2n+2
• What are the key points about alkenes?

  • Similar to alkanes but with a double bond
  • Unsaturated (contains double bond)
  • Chemical formula: C_nH_2n
• What are the key points about isomers?

  • Same chemical formula, different structures
  • Cycloalkanes and alkenes with same carbons are isomers
• What are the key points about addition reactions?

  • Involves a double bond adding onto another molecule
  • Test for unsaturation: bromine solution decolourisation