6.6.2 Reactions of Alcohols

• What are the three types of reactions alcohols undergo?

  Oxidation, substitution, elimination
• The type of alcohol reaction depends on its structure and the reagent
• Primary alcohols oxidize to aldehydes and then carboxylic acids.
• Match the reagent with the product of an alcohol reaction:

  Acidified potassium dichromate ↔️ Aldehyde/Ketone/Carboxylic acid

  Phosphorus halides (PCl5/PCl3) ↔️ Haloalkanes

  Concentrated sulfuric acid ↔️ Alkenes
• What type of alcohol reaction produces alkenes?

  Elimination
• What are the three main types of reactions alcohols undergo?

  Oxidation, substitution, elimination
• Primary alcohols oxidize to aldehydes and then to carboxylic acids
• Concentrated sulfuric acid is used in the elimination reaction of alcohols to form alkenes.
• Order the reactivity of hydrogen halides in reactions with alcohols from highest to lowest.

  1️⃣ HI

  2️⃣ HBr

  3️⃣ HCl
• The oxidation of a primary alcohol with acidified potassium dichromate produces an aldehyde, a ketone, or a carboxylic acid
• What product is formed when ethanol reacts with PCl5?

  Chloroethane
• Ethanol is oxidized to ethanal and then to ethanoic acid using acidified potassium dichromate.
• What type of product is formed when a secondary alcohol is oxidized?

  Ketone
• Tertiary alcohols are resistant to oxidation.
• Match the alcohol type with its oxidation product:

  Primary alcohol ↔️ Aldehyde/Carboxylic acid

  Secondary alcohol ↔️ Ketone

  Tertiary alcohol ↔️ No reaction
• Alcohols undergo dehydration reactions to form alkenes
• What is formed when ethanol is dehydrated with concentrated sulfuric acid at 180°C?

  Ethene
• The dehydration of ethanol to ethene requires a strong acid to protonate the hydroxyl group.
• Alcohols react with hydrogen halides in a substitution reaction to form haloalkanes
• What product is formed when ethanol reacts with HBr in the presence of concentrated sulfuric acid and heat?

  Bromoethane