Moderate

The highest melting point is observed by:

Correct answer: B. Pentanoic acid

  • A. Butanoic acid
  • B. Pentanoic acid
  • C. Propanoic acid
  • D. HCI

Explanation

The highest melting point is observed in option 2) Pentanoic acid. Boiling point of carboxylic acids increase with increasing molar mass of carboxylic acid. Pentanoic acid (also known as valeric acid) has a longer carbon chain compared to the other options, which are Butanoic acid (option 1) and Propanoic acid (option 3). The longer carbon chain in Pentanoic acid results in stronger intermolecular forces (Van der Waals forces) between its molecules. These stronger forces require more energy to break, leading to a higher melting point for Pentanoic acid compared to Butanoic acid and Propanoic acid.

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About Carboxylic Acids

Carboxylic acids are named and studied through the combined effects of the carbonyl and hydroxyl groups, their preparation, acidity and hydrogen bonding. Reactions include neutralisation, esterification, reduction and conversion into acid chlorides, anhydrides, esters and amides, with emphasis on how these derivatives interconvert.

Practise Carboxylic Acids

550 free Carboxylic Acids MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.

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