Alcohols

• What is the general formula for alcohols?

  C$nH_{2n+1}OH$
• How are alcohols named?

  They end in -ol with position numbers
• What is the name of the compound with the formula CH₃CH(OH)CH₂CH₃?

  butan-2-ol
• What is the name of the compound CH₃CH(OH)COOH?

  2-hydroxypropanoic acid
• How are multiple -OH groups indicated in alcohol naming?

  Using di, tri, and adding 'e' to stem
• What is the name of the compound with the formula CH₂CH(OH)CH₂OH?

  ethane-1,2-diol
• What defines a primary alcohol?

  One carbon attached to the carbon with -OH
• What defines a secondary alcohol?

  Two carbons attached to the carbon with -OH
• What defines a tertiary alcohol?

  Three carbons attached to the carbon with -OH
• What is the bond angle for H-C-H in alcohols?

  109.5°
• Why is the H-O-C bond angle in alcohols 104.5°?

  Due to lone pairs repelling more than bonding pairs
• Why do alcohols have high boiling points?

  Due to hydrogen bonding between molecules
• Why can smaller alcohols dissolve in water?

  They can form hydrogen bonds with water
• What is the oxidizing agent that causes alcohols to oxidize?

  Potassium dichromate (K₂Cr₂O₇)
• What happens during the partial oxidation of primary alcohols?

  They are converted to aldehydes
• What is the reagent used for partial oxidation of primary alcohols?

  Potassium dichromate (VI) and dilute sulfuric acid
• What is the observation when primary alcohols are oxidized?

  Orange dichromate reduces to green Cr³⁺
• How is the oxidation of primary alcohols represented in a simplified form?

  Using [O] for the oxidizing agent
• What is the correct way to write the formula of an aldehyde?

  Write CHO, not COH
• What is the reaction for the full oxidation of primary alcohols?

  Primary alcohols convert to carboxylic acids
• What conditions are needed for full oxidation of primary alcohols?

  Excess dichromate and heat under reflux
• What is the observation during full oxidation of primary alcohols?

  Orange dichromate reduces to green Cr³⁺
• What is the purpose of reflux in organic reactions?

  To prevent organic vapours from escaping
• What should never be done with the end of a condenser during reflux?

  Never seal the end to prevent pressure build-up
• What are anti-bumping granules used for?

  To prevent vigorous, uneven boiling
• What is the reaction for the oxidation of secondary alcohols?

  Secondary alcohols convert to ketones
• What is the reagent used for the oxidation of secondary alcohols?

  Potassium dichromate (VI) and dilute sulfuric acid
• What is the observation during the oxidation of secondary alcohols?

  Orange dichromate reduces to green Cr³⁺
• Why can't tertiary alcohols be oxidized by potassium dichromate?

  There is no hydrogen on the carbon with -OH
• How can aldehydes be distinguished from ketones?

  Aldehydes can be oxidized, ketones cannot
• What is Tollens’ reagent used for?

  To oxidize aldehydes to carboxylic acids
• What is the observation when aldehydes react with Tollens’ reagent?

  A silver mirror forms in the test tube
• What happens to silver(I) ions during the reaction with aldehydes?

  They are reduced to silver atoms
• What is the reaction equation for aldehydes with Tollens’ reagent?

  CH₃CHO + 2Ag⁺ + H₂O → CH₃COOH + 2Ag + 2H⁺
• What are the types of alcohols based on carbon attachment?

  • Primary: 1 carbon attached to -OH
  • Secondary: 2 carbons attached to -OH
  • Tertiary: 3 carbons attached to -OH
• What are the steps in the oxidation of primary alcohols?

  1. Partial oxidation to aldehyde
  2. Full oxidation to carboxylic acid
  3. Use potassium dichromate and dilute sulfuric acid
• What are the steps in the oxidation of secondary alcohols?

  1. Oxidation to ketone
  2. Use potassium dichromate and dilute sulfuric acid
  3. Heat under reflux
• What are the key features of distillation apparatus?

  • Collect distillate at boiling point
  • Thermometer bulb at T junction
  • Water in at bottom of condenser
  • Use electric heaters for safety
• What are the key features of reflux apparatus?

  • Prevents vapours from escaping
  • Never seal the end of the condenser
  • Use anti-bumping granules
• What are the observations during oxidation reactions?

  • Orange dichromate reduces to green Cr³⁺
  • Silver mirror forms with Tollens’ reagent