Comparison of Alkanoic Acid | Chemistry for JAMB PDF Download

Introduction

Alkanoic acids, also known as carboxylic acids, are organic compounds that contain the carboxyl functional group (-COOH). These compounds are characterized by their ability to donate a proton (H⁺) and form carboxylate ions. In this discussion, we will compare the properties and characteristics of different types of alkanoic acids.

Methanoic Acid (Formic Acid)

• Simplest alkanoic acid with the formula HCOOH.
• Occurs naturally in ant venom, bee venom, and stinging nettle.
• Pungent odor and is a strong reducing agent.
• Used as a preservative, an antibacterial agent, and in the production of dyes.

Ethanoic Acid (Acetic Acid)

• Commonly known as vinegar, with the formula CH₃COOH.
• Weak acid with a sour taste and a distinct smell.
• Found in vinegar, fruits, and alcoholic beverages.
• Used in the preparation of esters, plastics, and various organic compounds.

Propanoic Acid

• Formula C₂H₅COOH.
• Occurs naturally in milk, cheese, and sweat.
• Has a foul smell resembling rancid butter.
• Used in the production of pharmaceuticals, food additives, and herbicides.

Butanoic Acid

• Formula C₃H₇COOH.
• Has a strong odor similar to that of sweat or rancid butter.
• Found in cheeses and animal fats.
• Used as a flavoring agent and in the production of perfumes and plastics.

Pentanoic Acid

• Formula C₄H₉COOH.
• Known as valeric acid.
• Occurs naturally in valerian root and is responsible for its characteristic smell.
• Used as a flavoring agent and in the production of pharmaceuticals and esters.

Hexanoic Acid

• Formula C₅H₁₁COOH.
• Known as caproic acid.
• Found in milk, goat's cheese, and body odor.
• Used in the manufacture of artificial flavors, perfumes, and plasticizers.

Comparison

• The boiling points of alkanoic acids generally increase with the increase in the number of carbon atoms.
• As the chain length increases, the solubility of alkanoic acids in water decreases.
• The odors of alkanoic acids become stronger and more unpleasant with an increase in the number of carbon atoms.
• The acidity of alkanoic acids increases with an increase in the number of carbon atoms.
• Longer chain alkanoic acids generally have higher molar masses and densities.

Conclusion

Alkanoic acids exhibit various properties and characteristics based on their chain lengths. They have widespread applications in industries such as food, pharmaceuticals, and cosmetics. Understanding the differences between different types of alkanoic acids is essential in comprehending their diverse uses and chemical behavior.