Organic Synthesis

• What is the first step in the reaction involving alcoholic NH3 under heat and pressure?

  Step 1: H2SO4
• What is the purpose of warm hydrolysis in the reaction sequence?

  To facilitate the addition of water
• What type of reaction occurs with KOH aqueous?

  Nucleophilic substitution
• What is the role of UV light in the reaction with Br2 and Cl2?

  To initiate free radical substitution
• What is the product of heating KOH aqueous under reflux?

  Nucleophilic substitution
• What type of amine is produced from the reaction of an alkane with a halogenoalkane?

  Primary amine
• What is the product of the reaction between an alkene and an alcohol?

  Alcohol
• What is the result of the reaction between a ketone and a primary amine?

  Formation of an imine
• What is the effect of Na2Cr2O7/H+ on a primary alcohol?

  Partial oxidation
• What happens to a secondary alcohol when treated with Na2Cr2O7/H+?

  It undergoes oxidation
• What is the result of oxidizing a primary alcohol with excess oxidizing agent?

  Carboxylic acid
• What is the reagent used to form a nitrile?

  KCN in ethanol/water mixture
• What is the purpose of using high pressure and a catalyst in poly(alkene) production?

  To facilitate polymerization
• What is the product of the reaction between acyl chloride and alcohol?

  Esters
• What is the result of adding NaBH4 to a carbonyl compound?

  Reduction to alcohol
• What is the result of the reaction between a carboxylic acid and H2SO4?

  Esterification
• What is the purpose of using NaOH and acids in hydrolysis of esters and amides?

  To break down the ester or amide
• What is the reagent used for electrophilic substitution of aromatic compounds?

  Conc nitric acid + conc sulfuric acid
• What is the observation when aldehydes react with Tollen's reagent?

  Silver mirror forms
• What is the result of the reaction between aldehydes and Fehling's solution?

  Red precipitate of Cu2O
• What happens when a carboxylic acid reacts with sodium carbonate?

  Effervescence of CO2 evolves
• What is the observation when primary and secondary alcohols are oxidized?

  Orange to green colour change
• What is the purpose of using a Liebig condenser in reflux?

  To prevent vapours from escaping

  
• What is the function of anti-bumping granules in distillation?

  To prevent vigorous boiling
• Why should the end of the condenser not be sealed?

  To prevent gas pressure buildup
• What is the purpose of using electric heaters for organic chemicals?

  To avoid fire hazards
• What is the process of fractional distillation used for?

  To separate liquids with different boiling points
• How can the purity of a liquid be determined?

  By measuring its boiling point
• What happens to the boiling point of a liquid under changing pressure?

  It can change the boiling point
• What is the first step in the recrystallization process?

  Dissolve the impure compound in hot solvent
• Why is it important to use a minimum volume of solvent in recrystallization?

  To obtain a saturated solution
• What is the purpose of cooling the filtered solution in recrystallization?

  To allow crystals to reform
• What is the role of the Buchner flask in the recrystallization process?

  To speed up the filtration
• What is the purpose of washing the crystals with distilled water?

  To remove soluble impurities
• What indicates a pure sample when measuring melting point?

  A sharp melting point value
• What happens to the melting point of a sample with impurities?

  It lowers and broadens the range
• What is the observation when testing for alkenes with bromine water?

  Orange colour decolourises
• What is the result of testing aldehydes with Fehling's solution?

  Blue solution to red precipitate
• What is the observation when a carboxylic acid reacts with sodium carbonate?

  Effervescence of CO2 evolves
• What is the result of the reaction between chloroalkane and warm silver nitrate?

  White precipitate of AgCl