(7) 20 questions

• what is a hydrocarbon

  a substance with molecules that contain only carbon and hydrogen atoms
• how many bonds does a carbon atom form

  four
• name the first four alkanes

  methane, ethane, propane, butane
• what is the general formula of an alkane

  CnH2n+2
• how does the boiling point change with the length of an alkane

  the longer the alkane molecule, the higher its boiling point
• what is the chemical formula for propane

  C3H8
• write the balanced symbol equation for the complete combustion of methane

  CH4 + 2O2 --> CO2 + 2H20
• why are alkenes more reactive than alkanes

  because they contain at least one C=C double bond (they are unsaturarted) so they have the capacity to make further bonds
• complete the reaction of cracking of octane: C8H18 --> C6H14 + ____

  C2H4
• pentene has 5 carbon atoms. give the formula of penetene


  C5H10
• why do alkenes burn with smoky flames

  due to incomplete combustion
• explain how a sample of butane can be told apart from a sample of butene

  add bromine water and shake. butene is an aklene and decolourises the bromine water (from orange to colourless). butane does not react so it stays orange
• what is the ideal temp range from the fermentation of glucose

  25C to 50C
• give the formula of the fourth member of the homologous series of alchols

  CH3CH2CH2OH or C4H9OH
• give the formula of the fourth member of the homologous series of carboxylic acids

  CH3CH2CH2COOH or C3H7COOH
• name the product of the complete combustion of ethanol

  carbon dioxide and water
• name the addition polymer formed when lots of styrene monomers join together

  polystyrene
• what is a diol

  a molecule with two hydroxyl (OH) groups
• name time type of reaction used to product polyesters

  condensation polymerisation
• name the bond between the carboxyl groups and the amino groups formed when amino acids join together

  peptide link