3. halogenoalkanes

• What do halogen alkanes contain?

  One or more halogens attached to alkanes
• How do you name halogen alkanes?

  Find the longest carbon chain first
• What prefixes are used for halogens in naming?

  Fluoro, chloro, bromo, iodo
• What order should halogen prefixes be listed in?

  Alphabetical order
• What is the prefix for two halogens of the same type?

  Di-
• What happens to boiling points of halogen alkanes down the group?

  Boiling points increase down the group
• What governs the boiling points of halogen alkanes?

  The strength of intermolecular forces
• Why do boiling points increase as you go down group seven?

  More electrons lead to stronger van der Waals forces
• Name three examples of nucleophiles.

  Cyanide, ammonia, hydroxide
• What type of bond do halogen alkanes have?

  A polar bond
• What is a nucleophile?

  A substance that donates electron pairs
• What do curly arrows represent in reactions?

  The movement of electron pairs
• What is the mechanism for halogen alkanes reacting with hydroxide ions?

  Nucleophilic substitution
• What conditions are needed for halogen alkanes to react with hydroxide ions?

  Warm aqueous sodium hydroxide
• What is the role of the Liebig condenser in reflux?

  To prevent volatile substances from escaping
• What happens to the carbon during nucleophilic substitution?

  It forms a bond with the nucleophile
• What is formed when a halogen is replaced by a hydroxide ion?

  An alcohol and a halide salt
• What do halogen alkanes react with to form nitriles?

  Cyanide ions
• What conditions are needed for halogen alkanes to react with cyanide ions?

  Warm ethanol and potassium cyanide
• What is produced when halogen alkanes react with ammonia?

  An amine and ammonium ion
• Why is excess ammonia needed in the reaction with halogen alkanes?

  To stabilize the intermediate product
• How does the reaction mechanism differ when ammonia is used?

  It forms an unstable intermediate before stabilizing
• What is the characteristic smell of amines?

  Fishy smell
• What is the overall reaction when a halogen alkane reacts with sodium hydroxide?

  Alcohol plus sodium halide
• What does the symbol 'X' represent in reactions?

  A halogen atom
• What is the product of the reaction between halogen alkanes and cyanide ions?

  A nitrile compound
• What is the significance of the lone pair in nucleophiles?

  It allows them to donate electrons
• How do the reactions of halogen alkanes with hydroxide ions and cyanide ions compare?

  Both involve nucleophilic substitution mechanisms
• What happens to the nitrogen atom in the amine product?

  It stabilizes by accepting a proton
• What is the charge of the ammonium ion produced?

  Positive charge
• What is the final product when halogen alkanes react with ammonia?

  An amine and ammonium ion
• Why do we need excess ammonia in the reaction?

  To ensure complete reaction with hydrogen
• What role does ammonia play in the reaction?

  Ammonia acts as a base
• What do bases do in chemical reactions?

  They accept protons
• What happens to the nitrogen during the reaction?

  The nitrogen stabilizes by accepting electrons
• How can we identify an amine?

  By its distinguishable fishy smell
• What is the formula for ammonium ion?

  NH4+
• What is produced when ammonia reacts in this mechanism?

  An amine and ammonium ion
• How does the reactivity of halogen alkenes change down the group?

  They become more reactive
• What determines the reactivity of halogen alkenes?

  Bond strength and bond enthalpy