alkenes->alkanes

• What is an addition reaction?

  An addition reaction is a chemical reaction where two or more molecules combine to form a single product molecule.
• How can alkanes be produced from alkenes?

  Alkenes can undergo electrophilic addition with hydrogen to produce alkanes.

  The C=C bond opens up and forms single bonds to each of the hydrogen bonds.
• What does hydrogenation of an alkene require?

  a nickel catalyst

  150 degrees Celsius
• Give an example of hydrogenation of an alkene?

  propene + hydrogen -> propane

  CH2CH3CH2 + H2 -> CH3CH2CH3
• What is this electrophilic addition reaction also known as?

  a hydrogenation reaction
• What is catalytic hydrogenation used in?

  The manufacture of margarine from unsaturated vegetable oils.
• Why do electrophilic addition reactions happen?

  because the double bond (C=C) is an area of high electron density, this attracts electrophiles
• What are electrophiles?

  Electrophiles are electron-deficient species that are attracted to electron-rich regions in a chemical reaction.

  They are electron-pair acceptors.
• What are some examples of electrophiles?

  Electrophiles include positively charged ions, like H+ and NO2+, and polar molecules (as the &+ atoms is attracted to places with lots of electrons).
• What is an addition polymer?

  Many monomers bonded together via rearrangement of bonds without the loss of any atom or molecule
• What are monomers, what form do they usually take?

  Molecules which combine to form a polymer.

  Usually have a C=C bond which breaks to leave a repeating pattern.