Concise Notes on Carboxylic Acids and Their Derivatives

Key Concepts

• Carboxylic Acids

  • Contain a carboxyl group (-COOH).
  • Have the highest boiling points of all functional groups.
  • Smaller carboxylic acids are water-soluble, while solubility decreases with increased carbon chain length.
  • Naming: Replace “-e” with “-oic acid” in the longest carbon chain with the carboxyl group.
  • Common examples: Formic acid (HCOOH), Acetic acid (CH₃COOH), Propionic acid (CH₃CH₂COOH).

• Esters

  • Formed from the reaction between carboxylic acids and alcohols.
  • Named using the alkyl part from the alcohol and the parent acid, ending in “-ate.”
  • Common flavors include raspberry (isobutyl methanoate) and banana (pentyl ethanoate).

• Amides

  • Derived from carboxylic acids by replacing the -OH with an amine.
  • Show higher boiling points compared to the corresponding acids due to more hydrogen bonding.
  • Naming: Replace “-ic acid” with “-amide.”

• Reactions of Carboxylic Acids

  • Can undergo esterification to form esters and can also form amides by reacting with amines.
  • Hydrolysis of esters and amides can regenerate carboxylic acids, facilitated by acid or base.

• Chemical Properties of Carboxylic Acids

  • Weak acids with dissociation constants (pKa) between 3 and 6.
  • Carboxylic acids exist in two forms: the acid form and the carboxylate ion form in basic conditions.

• Naming Carboxylate Ions

  • Derived from carboxylic acids by dropping “-ic acid” and adding “-ate.”

• Common Analgesics

  • Examples include Aspirin (acetylsalicylic acid), Ibuprofen, and Acetaminophen. Acetaminophen has analgesic properties but lacks anti-inflammatory effects.

• Phosphoric Acid Derivatives

  • Polyprotic acid with multiple pKa values (2.15, 7.20, 12.37).