reaction mechanisms

• What are the two processes that occur when a covalent bond breaks?

  Heterolytic and homolytic fission
• What occurs during heterolytic fission?

  Uneven cleavage of the shared electron pair
• What charge does the atom that retains both bonding electrons acquire during heterolytic fission?

  Negative charge
• What does the atom that loses both electrons become during heterolytic fission?

  A carbocation
• In what type of reactions is heterolytic fission common?

  Reactions in solution or involving ions
• Provide an example of heterolytic fission.

  1. Y ➔ X+ + Y-
• What occurs during homolytic fission?

  Even cleavage of the shared electron pair
• Why are radicals highly reactive?

  Due to their unpaired electrons
• In what type of reactions is homolytic fission commonly observed?

  Gas-phase reactions and nonpolar substances
• Provide an example of homolytic fission.

  1. Y ➔ X• + Y•
• What do reaction mechanisms depict?

  The sequential steps of reactants transforming into products
• What do curly arrows represent in reaction mechanisms?

  The movement of electron pairs
• What are the steps for drawing curly arrows in reaction mechanisms?

  1. Initiate at the bond or lone pair
  2. Conclude at the new location of electrons
  3. Ensure arrow direction represents electron movement
• What is the mechanism for the reaction CH3Cl + NaOH?

  It shows curly arrows indicating electron movement
• What are the key types of organic reactions?

  • Addition
  • Elimination
  • Substitution
  • Hydrolysis
  • Oxidation
  • Reduction
• What occurs during an addition reaction?

  Two or more molecules join to form a larger molecule
• What happens in an elimination reaction?

  A small group detaches from a larger molecule
• What is a substitution reaction?

  One atom or group is replaced by another
• What occurs during hydrolysis?

  A molecule splits by incorporating H+ and OH- from water
• What does oxidation represent in a reaction?

  A species loses electrons to an oxidizing agent
• How is oxidation represented in equations?

  By [O]
• What does reduction represent in a reaction?

  A species gains electrons from a reducing agent
• How is reduction represented in equations?

  By [H]
• What are the types of reagents in organic reactions?

  • Nucleophiles: Electron pair donors
  • Electrophiles: Electron pair acceptors
  • Radicals: Species with unpaired electrons
• What are nucleophiles?

  Electron pair donors with lone pairs or negative charges
• Give examples of nucleophiles.

  Halide ions, oxygen, and nitrogen atoms
• What are electrophiles?

  Electron pair acceptors that are electron deficient
• Give examples of electrophiles.

  H+ ions, alkenes, and benzene rings
• What are radicals in organic chemistry?

  Species with one or more unpaired electrons
• Why are radicals highly reactive?

  Due to their unpaired electrons
• Give examples of radicals.

  Cl• and CH2Cl• radicals