6.5.1 Properties of Halogenoalkanes

• What is the general formula for halogenoalkanes?

  $R - X$
• A halogen atom can be fluorine, chlorine, bromine, or iodine
• The boiling point of halogenoalkanes increases down the halogen group due to stronger London dispersion forces.
• Arrange the halogens in order of increasing boiling point when bonded in halogenoalkanes:

  1️⃣ Fluorine

  2️⃣ Chlorine

  3️⃣ Bromine

  4️⃣ Iodine
• Why are halogenoalkanes insoluble in water?

  Non-polar nature
• The polar C-X bond in halogenoalkanes makes the carbon atom susceptible to nucleophilic attack.
• What is the general reaction for nucleophilic substitution in halogenoalkanes?

  R - X + Nu^ - \rightarrow R - Nu + X^ -</latex>
• Elimination reactions in halogenoalkanes require heat and a strong base
• Match the reaction type with its conditions:

  Nucleophilic Substitution ↔️ Polar protic solvents

  Elimination ↔️ Strong base
• Which type of halogenoalkane favors SN1 reactions?

  Tertiary
• E2 reactions in halogenoalkanes favor primary halogenoalkanes and a strong base
• Nucleophilic substitution in halogenoalkanes always results in the formation of an alkene.

  False
• Arrange the following reactions in order of their typical conditions:

  1️⃣ Nucleophilic Substitution (SN1)

  2️⃣ Nucleophilic Substitution (SN2)

  3️⃣ Elimination (E1)

  4️⃣ Elimination (E2)
• What is an alkyl group in the context of halogenoalkanes?

  Portion of an alkane molecule
• Larger halogens increase London dispersion forces, leading to higher boiling points
• Halogenoalkanes are highly soluble in water due to their polar nature.

  False
• Halogenoalkanes exhibit distinct physical properties due to the presence of halogen
• The boiling point of halogenoalkanes increases down the halogen group from fluorine to iodine.
• The density of halogenoalkanes increases down the halogen group due to greater atomic mass
• Halogenoalkanes are highly soluble in polar water.

  False
• Larger and more electronegative halogen atoms induce a greater dipole moment in the $C - X$ bond
• What makes halogenoalkanes prone to nucleophilic attack?

  Polar C-X bond
• Match the nucleophilic substitution mechanism with its characteristics:

  SN1 ↔️ Two-step, prefers tertiary halogenoalkanes

  SN2 ↔️ Single-step, prefers primary halogenoalkanes
• The SN1 mechanism uses polar protic solvents
• The SN2 mechanism prefers polar aprotic solvents.
• What type of reaction forms an alkene from a halogenoalkane?

  Elimination
• The E1 mechanism involves two steps and prefers tertiary halogenoalkanes with strong heat
• The E2 mechanism is a single-step reaction that prefers primary halogenoalkanes.
• Match the reaction type with its products:

  Nucleophilic Substitution ↔️ Substituted alkane

  Elimination ↔️ Alkene
• What are the two main types of reactions halogenoalkanes undergo?

  Nucleophilic substitution and elimination
• In nucleophilic substitution, a halogen atom is replaced by a nucleophile
• Steps of the SN1 mechanism

  1️⃣ Formation of a carbocation

  2️⃣ Attack by a nucleophile
• The SN2 mechanism is favored by polar aprotic solvents.
• What is removed from a halogenoalkane during an elimination reaction?

  HX
• The E2 mechanism favors primary halogenoalkanes with a strong base
• The E1 mechanism requires strong heat and prefers tertiary halogenoalkanes.
• Which halogen in a halogenoalkane results in the highest reactivity?

  Iodine
• Carbon chain length and branching can affect reactivity due to steric hindrance
• Halogenoalkanes are effective solvents due to their polarity.
• What type of substances are halogenoalkanes used to dissolve due to their polarity?

  Wide range of substances