Nucleophillic Substitution

• What is nucleophilic substitution?

  A reaction where one functional group is replaced
• What type of molecules are involved in nucleophilic substitution reactions?

  Halogenoalkane molecules
• What do mechanisms in chemistry illustrate?

  How a reaction works and bond changes
• What is the general equation for nucleophilic substitution of a halogenoalkane?

  CH₃CH₂X + Nu⁻ → CH₃CH₂Nu + X⁻
• What does the 'X' represent in the nucleophilic substitution equation?

  One of the halogens (F, Cl, Br, I)
• What does the 'Nu' represent in the nucleophilic substitution equation?

  A nucleophile attacking the polar molecule
• How does a nucleophile attack a carbon atom in nucleophilic substitution?

  By using a lone pair of electrons
• What do curly arrows represent in reaction mechanisms?

  The movement of an electron pair
• What happens to the carbon-halogen bond during nucleophilic substitution?

  It breaks when the nucleophile attaches
• What do halogenoalkanes produce when they react with hydroxides?

  Alcohols
• What is the structure of a nitrile?

  It has a CN group with a triple bond
• How is ethanenitrile formed from halogenoalkanes?

  By warming with ethanolic potassium cyanide
• What is the structure of an amine?

  R₃N, where R can be hydrogen or another group
• How do amines form from halogenoalkanes?

  By reacting with excess ethanolic ammonia
• What determines the reactivity of halogenoalkanes?

  The strength of the carbon-halogen bond
• Which carbon-halogen bond is the strongest?

  C-F bond
• Which carbon-halogen bond is the weakest?

  C-I bond
• How does bond enthalpy affect the rate of nucleophilic substitution?

  Lower bond enthalpy leads to faster substitution
• What are the key points of nucleophilic substitution reactions?

  • Occur between halogenoalkane and nucleophile
  • Nucleophile attacks δ+ carbon, breaking carbon-halogen bond
  • One bond is formed (nucleophile to carbon) and one is broken (carbon-halogen)
  • Curly arrows show electron movement from bonds or lone pairs