17.2.2 Esters

• What is the functional group of esters?

  -COOR
• Esters form through a process called esterification
• How is the nomenclature of esters determined?

  Alkyl group < carboxylate ion
• What is the functional group of esters?

  -COOR
• Esters are formed when a carboxylic acid reacts with an alcohol
• What is the name of the ester formed when acetic acid reacts with methanol?

  Methyl acetate
• Steps for naming esters

  1️⃣ Identify the alkyl group from the alcohol

  2️⃣ Identify the carboxylate ion from the carboxylic acid

  3️⃣ Replace '-ic acid' with '-ate'

  4️⃣ Combine the alkyl group and carboxylate ion
• The alkyl group in ester nomenclature is derived from the alcohol.
• Which alcohol forms the alkyl group 'methyl' in ester nomenclature?

  Methanol
• The carboxylate ion in ester nomenclature is derived from the carboxylic acid
• Esters with smaller alkyl groups are more soluble in water than esters with larger alkyl groups.
• Why do esters have lower boiling points compared to carboxylic acids?

  Weaker intermolecular forces
• Many esters have pleasant fruity odors.
• Esters have lower boiling points than carboxylic acids
• What is the functional group of esters?

  -COOR
• The alkyl group in ester nomenclature is derived from the alcohol.
• Which alcohol forms the alkyl group 'ethyl' in ester nomenclature?

  Ethanol
• The carboxylate ion in ester nomenclature is derived from the carboxylic acid
• Match the nomenclature principle with its explanation:

  Alkyl group ↔️ Derived from alcohol, named first

  Carboxylate ion ↔️ Derived from carboxylic acid, named last

  Final name ↔️ Combines alkyl and carboxylate
• Esters with smaller alkyl groups are more soluble in water than esters with larger alkyl groups.
• Why do esters have lower boiling points compared to carboxylic acids?

  Weaker intermolecular forces
• What is named first in the nomenclature of esters?

  Alkyl group
• The carboxylate ion is named by replacing the "-ic acid" of the carboxylic acid with -ate
• When acetic acid reacts with methanol, the ester formed is methyl acetate.
• What is the chemical formula for the ester formed when acetic acid reacts with methanol?

  $CH_{3}COOCH_{3}$
• Steps in naming esters according to nomenclature principles

  1️⃣ Identify the alkyl group from the alcohol

  2️⃣ Identify the carboxylate ion from the carboxylic acid

  3️⃣ Combine the names to form the final ester name
• Why are esters with smaller alkyl groups soluble in water?

  Hydrogen bonding
• Esters have lower boiling points compared to carboxylic acids due to weaker intermolecular forces
• Many esters have pleasant fruity odors, making them useful in perfumes and flavorings.
• What is the process of preparing esters from carboxylic acids and alcohols called?

  Esterification
• An acid catalyst in esterification enhances the reaction rate by protonating the carbonyl oxygen
• Steps to shift the equilibrium in esterification to favor ester formation

  1️⃣ Use an acid catalyst

  2️⃣ Apply heat

  3️⃣ Remove water
• Esterification uses heat and sulfuric acid as a catalyst to produce esters.
• What is the process called that splits an ester using water in the presence of an acid or base catalyst?

  Hydrolysis
• Saponification involves the reaction of an ester with a strong base
• Saponification produces a sodium salt of the carboxylic acid and an alcohol.
• What catalyst is used in the hydrolysis of an ester under acidic conditions?

  $H^ +$
• Match the reaction with its conditions:

  Hydrolysis ↔️ $H_{2}O$, acid or base

  Saponification ↔️ $NaOH$, heat
• Steps in acid-catalyzed hydrolysis of an ester

  1️⃣ Protonation of the carbonyl oxygen

  2️⃣ Water attacks the carbonyl carbon

  3️⃣ Formation of the carboxylic acid and alcohol
• Base-catalyzed hydrolysis of esters is an irreversible reaction.