Elimination Reactions

• What is an elimination reaction?

  A reaction where a small group of atoms breaks away
• What happens to the small group of atoms in an elimination reaction?

  They break away from a larger molecule
• What is not replaced in an elimination reaction?

  The small group of atoms
• How does a halogen elimination reaction occur?

  By warming a halogen alkane with hydroxide ions
• What is produced when a halogen alkane reacts with hydroxide ions?

  An alkene and water
• What is the equation for the elimination reaction of 2-bromopropane with potassium hydroxide?

  $CH_3CHBrCH_3 +$$KOH \rightarrow CH_3CH=$$CH_2 +$$H_2O +$$KBr$
• What happens to hydrogen and bromine in the elimination reaction?

  Hydrogen and bromine are eliminated
• What is the role of hydroxide ions in the elimination reaction?

  They act as a base and remove protons
• What is the result of the elimination reaction involving halogenated compounds?

  Formation of alkenes and elimination of halogens
• How can you influence the type of reaction that occurs with halogenated compounds?

  By changing the reaction conditions
• What is a nucleophilic substitution reaction?

  A reaction where a nucleophile replaces a leaving group
• How does nucleophilic substitution differ from elimination reactions?

  Nucleophilic substitution replaces a group, elimination removes it
• What factors can influence whether a nucleophilic substitution or elimination reaction occurs?

  Reaction conditions and substrate structure
• What happens when you react a halogen alkane with water under reflux?

  You will predominantly get nucleophilic substitution
• What is the product of reacting bromomethane with water?

  Methanol and bromide ion
• Why does the reaction with water produce methanol instead of an alkene?

  Because water acts as a nucleophile
• How does the presence of a strong base affect the reaction outcome?

  It favors elimination over substitution
• What is the significance of the δ+ carbon atom in nucleophilic reactions?

  It is attacked by nucleophiles
• What does the presence of δ+ and δ- indicate in a molecule?

  Polar covalent bonds exist in the molecule
• How does the nucleophile interact with the δ+ carbon atom?

  It donates an electron pair to form a bond
• What is the effect of changing conditions on nucleophilic substitution reactions?

  It can shift the balance towards elimination or substitution
• What is the expected outcome when a nucleophile attacks a δ+ carbon atom?

  Formation of a new bond with the nucleophile
• What is the role of the leaving group in nucleophilic substitution?

  It departs to allow the nucleophile to bond
• Why is the leaving group important in nucleophilic substitution reactions?

  It determines the reaction's feasibility and speed
• How does the structure of the substrate affect nucleophilic substitution?

  It influences the stability of the transition state
• What happens when a strong nucleophile reacts with a primary halide?

  Substitution is favored over elimination
• What is the general outcome of nucleophilic substitution reactions?

  Formation of a new compound with a nucleophile
• How does the solvent affect nucleophilic substitution reactions?

  It can stabilize or destabilize the transition state
• What is the relationship between nucleophilicity and basicity?

  Nucleophilicity is not always correlated with basicity
• How can you predict the outcome of a reaction involving a nucleophile?

  By analyzing the substrate and reaction conditions
• What is the significance of the δ- oxygen atom in nucleophilic reactions?

  It attracts the δ+ carbon atom
• How does the δ- oxygen atom interact with the carbon atom?

  It forms a bond with the carbon atom
• What is the overall effect of nucleophilic substitution on molecular structure?

  It alters the connectivity of atoms in the molecule
• What is the expected product when a nucleophile attacks a δ+ carbon atom?

  A new compound with the nucleophile attached
• What is the role of the nucleophile in substitution reactions?

  It donates an electron pair to form a bond
• Why is the nucleophile important in substitution reactions?

  It initiates the reaction by attacking the substrate
• How does the strength of the nucleophile affect the reaction rate?

  A stronger nucleophile increases the reaction rate
• What is the expected outcome when a weak nucleophile reacts with a substrate?

  Slower reaction rate and possible substitution
• What is the significance of the leaving group in nucleophilic substitution?

  It allows the nucleophile to bond with the substrate
• How does the leaving group affect the reaction mechanism?

  A better leaving group speeds up the reaction