alkene facts

• What are alkenes?

  Unsaturated hydrocarbons that contain at least one C=C bond made up of a pi bond and a sigma bond.
• What is the general formula of alkenes?

  CnH2n
• How is a pi bond formed?

  Electrons in the adjacent p orbitals overlap above and below the carbon atoms.

  Pi bonds can only be made after a sigma bond is formed.
• What bond restricts the rotation of carbon atoms in alkenes?

  pi bond
• What is the angle and shape of a C=C bond?

  120 degrees

  Trigonal planar
• Are alkenes more or less reactive than alkanes? Why?

  Alkenes are more reactive than alkanes due to the high electron density of the double bond and the fact the pi-bond is slightly easier to break.
• What intermolecular forces do alkenes have?

  Only London dispersion forces due to non-polar bonds.
• Are alkenes soluble in water? Why?

  No. Alkenes are insoluble in water because they are nonpolar molecules and water is a polar solvent.
• What are the types of isomers that can be formed using alkenes?

  E/Z isomers, due to the restricted rotation.

  Cis-trans isomers- if 2 of the same substituents are attached to each carbon
• What is an electrophile?

  A species that are electron pair acceptors
• What is the most stable type of carbocation intermediate? Why?

  Alkyl groups have a positive inductive effect, so the most stable carbocation is the one bonded to the most other carbon atoms i.e: tertiary carbocation.