Organic Mechanism

• What is the chemical formula for ethane?

  C₂H₆
• What is the chemical formula for bromine?

  Br₂
• What is the significance of δ+ and δ- in the context of molecular polarity?

  δ+ indicates a partial positive charge, while δ- indicates a partial negative charge.
• What is the role of UV light in the initiation step of free radical substitution?

  UV light is essential for breaking the Br-Br bond to generate free radicals.
• What are the types of nucleophilic substitution reactions of halogenoalkanes?

  • With aqueous hydroxide ions
  • With cyanide ions
  • With ammonia
• What are the types of electrophilic addition reactions of alkenes?

  • With bromine
  • With hydrogen bromide
  • With sulfuric acid
• What is the role of concentrated H₂SO₄ or H₃PO₄ in acid-catalyzed elimination mechanisms?

  They provide H⁺ ions necessary for the elimination process.
• What is the mechanism for the acid-catalyzed addition of water to ethene?

  1. H⁺ from concentrated H₃PO₄ protonates ethene.
  2. Water adds to the carbocation formed.
  3. Resulting in the formation of an alcohol.
• What is the oxidizing agent used for the oxidation of primary alcohols or aldehydes?

  K₂Cr₂O₇/H⁺
• What are the conditions for nucleophilic substitution with KCN in an ethanol/water mixture?

  • Use KCN
  • In an ethanol/water mixture
• What are the conditions for free radical substitution with Br₂ or Cl₂?

  • Use UV light
  • In the presence of bromine or chlorine
• What are the conditions for nucleophilic substitution with KOH aqueous?

  • Use KOH in aqueous solution
  • Heat under reflux
• What are the types of organic compounds mentioned in the study material?

  • Alkane
  • Halogenoalkane
  • Alkene
  • Alcohol
  • Ketone
  • Aldehyde
  • Carboxylic acid
  • Diol
  • Dihalogenoalkane
  • Nitrile
  • Poly(alkene)
• What is the chemical structure represented by H3C-C-H-H-Br?

  It is a halogenoalkane with a bromine atom.
• What does the notation δ+ and δ- indicate in a molecule?

  It indicates partial positive and partial negative charges, respectively.
• What is the role of UV light in the initiation step of free radical substitution?

  It is essential for breaking the Br-Br bond to form free radicals.
• What are the three steps of free radical substitution in alkanes with bromine?

  1. Initiation: Formation of bromine radicals.
  2. Propagation: Reaction of radicals with alkanes and bromine.
  3. Termination: Combination of radicals to form stable products.
• What is the product of the reaction CH3CH2. + Br2 in the propagation step?

  CH3CH2Br + Br.
• What is the mechanism of nucleophilic substitution of halogenoalkanes with aqueous hydroxide ions?

  It involves the replacement of the halogen atom by a hydroxyl group.
• What is the result of the elimination of halogenoalkanes with ethanolic hydroxide ions?

  It produces alkenes by removing the halogen and a hydrogen atom.
• What is the electrophilic addition of alkenes with bromine?

  It is a reaction where bromine adds across the double bond of an alkene.
• What is the role of concentrated sulfuric acid in acid-catalyzed elimination mechanisms?

  It provides protons (H+) to facilitate the elimination of water.
• What are the steps involved in the acid-catalyzed addition mechanism for the hydration of ethene?

  1. Protonation of ethene to form a carbocation.
  2. Nucleophilic attack by water.
  3. Deprotonation to form an alcohol.
• What is the product of the reaction between ammonia and a halogenoalkane?

  It forms an amine and ammonium bromide.
• What is the significance of the lone pair of electrons on the nitrogen in amines?

  It allows amines to act as nucleophiles in reactions.
• What are the types of amines formed from nucleophilic substitution reactions with halogenoalkanes?

  • Primary amine
  • Secondary amine
  • Tertiary amine
  • Quaternary ammonium salt
• What is the product of the reaction between a primary amine and a halogenoalkane?

  It forms a secondary amine.
• What is the nucleophilic addition-elimination mechanism?

  It involves the addition of a nucleophile followed by the elimination of a leaving group.
• What are the steps in the electrophilic substitution mechanism for aromatic compounds?

  1. Generation of the electrophile.
  2. Attack of the electrophile on the aromatic ring.
  3. Deprotonation to restore aromaticity.
• What is the equation for the formation of the electrophile in electrophilic substitution?

  HNO3 + 2H2SO4 → NO2+ + 2HSO4- + H3O+
• What is the role of AlCl3 in electrophilic substitution reactions?

  It acts as a catalyst to generate the electrophile.
• What are the conditions for nucleophilic substitution reactions of ammonia/amines?

  • Alcoholic NH3
  • Heat under pressure
  • Aqueous KOH
• What is the product of the reaction between acyl chloride and ammonia?

  It forms a primary amide.
• What are the different types of reactions summarized in the A-level AQA Chemistry mechanism summary?

  • Nucleophilic Substitution
  • Electrophilic Addition
  • Free Radical Substitution
  • Acid-catalyzed elimination
  • Oxidation reactions
• What is the significance of NaBH4 in organic reactions?

  It is used as a reducing agent in nucleophilic addition reactions.
• What is the product of the reaction between a carboxylic acid and alcohol in esterification?

  It forms an ester.
• What are the conditions for esterification reactions?

  • Heat
  • Presence of concentrated sulfuric acid
• What is the product of the reaction between a nitrile and water?

  It forms a hydroxynitrile.
• What is the role of concentrated sulfuric acid in the esterification process?

  It acts as a catalyst to speed up the reaction.
• What are the types of compounds that can be hydrolyzed by NaOH and acids?

  • Esters
  • Amides