3.3.9.3 Hydrolysis of Esters

    Cards (41)

    • An ester is formed by the reaction between a carboxylic acid and an alcohol
    • In basic hydrolysis of an ester, the carboxylate ion and the original alcohol are formed.
    • What are the reactants in the acidic hydrolysis of an ester?
      Ester and water
    • What two conditions are necessary for ester hydrolysis to occur?
      Acidic or basic
    • Which molecule acts as a nucleophile in the nucleophilic addition stage of acid-catalyzed hydrolysis?
      Water
    • What type of ion is formed in the breakdown stage of base-catalyzed hydrolysis?
      Carboxylate ion
    • In the base-catalyzed mechanism, the hydroxide ion acts as a nucleophile
    • The base-catalyzed hydrolysis of esters shares the same tetrahedral intermediate as the acid-catalyzed mechanism.
    • In basic conditions, the hydrolysis of an ester produces a carboxylate ion and an alcohol
    • Order the steps of the acid-catalyzed hydrolysis mechanism:
      1️⃣ Protonation of carbonyl oxygen
      2️⃣ Water attacks carbonyl carbon
      3️⃣ Formation of tetrahedral intermediate
      4️⃣ Breakdown to carboxylic acid and alcohol
    • The tetrahedral intermediate in acid-catalyzed hydrolysis breaks down to form a carboxylic acid, alcohol, and the acid catalyst.

      True
    • Water acts as a nucleophile in the acid-catalyzed hydrolysis of esters.

      True
    • Acid-catalyzed hydrolysis of an ester forms the original carboxylic acid and alcohol.

      True
    • The general structure of an ester is R-COO-R', where R and R' represent the hydrocarbon groups
    • In esterification, water (H₂O) is eliminated to form the ester linkage, resulting in the structure R-COO-R'
    • In acid-catalyzed hydrolysis, the carbonyl oxygen of the ester is protonated by the acid
    • In base-catalyzed hydrolysis, the hydroxide ion attacks the carbonyl carbon of the ester.
    • How does the base-catalyzed hydrolysis of esters differ from the acid-catalyzed hydrolysis?
      Different reaction mechanisms
    • What ion is produced in the base-catalyzed hydrolysis of an ester instead of a carboxylic acid?
      Carboxylate ion
    • The general structure of an ester is R-COO-R', where R and R' represent hydrocarbon groups.

      True
    • Hydrolysis of esters can occur under acidic or basic conditions.
      True
    • In the nucleophilic addition step of acid-catalyzed hydrolysis, water acts as a nucleophile
    • The acid catalyst protonates the carbonyl oxygen of the ester, making the carbonyl carbon more electrophilic
    • Base-catalyzed hydrolysis of esters uses hydroxide ions (OH⁻) under alkaline conditions.
    • Acid hydrolysis produces the original carboxylic acid, while base hydrolysis produces the carboxylate ion.

      True
    • What is the chemical reaction called where a compound is broken down using water?
      Hydrolysis
    • Under what conditions can ester hydrolysis occur?
      Acidic or basic
    • What is the process called when an ester is formed from a carboxylic acid and an alcohol?
      Esterification
    • In acidic hydrolysis, an acid catalyst helps break the ester bond.
      True
    • Acid-catalyzed hydrolysis regenerates the acid catalyst.
      True
    • Base-catalyzed hydrolysis reverses the esterification reaction to form the carboxylate ion and alcohol.

      True
    • The tetrahedral intermediate in base-catalyzed hydrolysis includes the hydroxide group and ester groups.
      True
    • What is the role of hydroxide ions in the activation stage of the base-catalyzed hydrolysis mechanism?
      Acts as a nucleophile
    • What is the chemical process called where a compound is broken down by water?
      Hydrolysis
    • What happens during the protonation step in the acid-catalyzed hydrolysis of an ester?
      Carbonyl oxygen is protonated
    • What does the acid-catalyzed mechanism efficiently hydrolyze esters into?
      Carboxylic acid and alcohol
    • Steps in the acid-catalyzed hydrolysis mechanism
      1️⃣ Protonation of the carbonyl oxygen
      2️⃣ Nucleophilic addition by water
      3️⃣ Formation of a tetrahedral intermediate
      4️⃣ Breakdown to carboxylic acid and alcohol
    • In base-catalyzed hydrolysis, the final product is a carboxylate ion and an alcohol.
    • Match the application with its description:
      Saponification ↔️ Production of soap
      Biodegradation ↔️ Breakdown of fats and oils in the environment
      Digestion ↔️ Hydrolysis of triglycerides by lipases
    • The hydroxide ion attacks the carbonyl carbon in base-catalyzed hydrolysis.
      True
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