addition reactions of alkenes + polymerisation

• What are alkenes classified as?

  Unsaturated hydrocarbons
• What does the term "unsaturated" mean in alkenes?

  They contain at least one carbon-carbon double bond
• What is the functional group of alkenes?

  Carbon-carbon double bond
• What elements do hydrocarbons contain?

  Only hydrogen and carbon atoms
• Why can alkenes undergo addition reactions?

  The carbon-carbon double bond can open up
• What are the three types of addition reactions for alkenes?

  1. With hydrogen
  2. With water
  3. With halogens
• What is the alkene used in the hydrogen addition reaction?

  Propene
• What happens when hydrogen gas is added to propene?

  The double bond breaks and propane forms
• What is the product formed when propene reacts with hydrogen?

  Propane
• What is the alkene used in the water addition reaction?

  Ethene
• What conditions are required for the reaction of ethene with water?

  Catalyst and high temperatures
• What does water split into during the reaction with ethene?

  A hydrogen atom and an OH group
• What is the product formed when ethene reacts with water?

  Ethanol
• What is ethanol classified as?

  A type of alcohol
• How is ethanol separated from unreacted ethene and water?

  By cooling and fractional distillation
• Why is ethene easy to separate from the mixture?

  It has a relatively low boiling point
• What happens to ethanol during fractional distillation?

  It evaporates first due to lower boiling point
• What is the common halogen used in the addition reaction with alkenes?

  Bromine
• What happens when bromine is added to ethene?

  It forms dibromoethane and decolorizes
• How can we distinguish alkenes from alkanes using bromine water?

  Alkenes decolorize bromine water, alkanes do not
• What is the summary of alkenes' reactions with bromine water?

  • Alkenes can decolorize bromine water
  • Alkanes cannot decolorize bromine water
• What type of polymers are made using alkenes?

  Addition polymers
• What feature characterizes a molecule as an alkene?

  Presence of a carbon-carbon double bond
• Why are alkenes considered unsaturated?

  They contain a carbon-carbon double bond
• What happens to the double bond in alkenes under the right conditions?

  It can break to form new bonds
• What do three ethene molecules combine to form?

  One long chain polymer
• What is a drawback of drawing all monomers in polymerization reactions?

  It can involve hundreds of monomers
• How can we better represent the polymerization reaction?

  Show one monomer and repeating units
• What do repeating units in a polymer contain?

  Same group of atoms as the monomer
• How should the bonds of the monomer be drawn?

  Facing up and down
• What do the empty bonds in the repeating unit represent?

  Bonds extending through the brackets
• What does the variable 'n' represent in polymerization?

  Number of repeating units
• How do you write the equation for addition polymerization of butane?

  Redraw butane in the correct format
• What is the first step in drawing butane for polymerization?

  Identify the double bond
• How should hydrogen atoms be represented in the drawing?

  Pointing straight up or down
• How do you simplify the large group in butane?

  Count carbons and hydrogens, write as C2H5
• Why is it important to draw the bond from carbon to carbon?

  To accurately represent the structure
• What do you add to the drawing to indicate repeating units?

  Add brackets and 'n'
• How do you represent the reaction arrow in polymerization?

  Draw an arrow between reactants and products
• How do you name the resulting polymer?

  Use "poly" followed by monomer's name