Alkanoic acids have low volatility compared with alkanols because they?

 Alkaonic acids have low volatility compared with alkanols because they?

• A. are more polar than alkaonls
• B. have two oxygen atoms while alkanols have one
• C. form hydrogen bonds while alkanols do not
• D. form two hydrogen bonds while alkanols form one

Correct Answer:

D. form two hydrogen bonds while alkanols form one

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🔹 Comparison: Alkanoic acids vs Alkanols

• Alkanols (alcohols): $-OH$ group → can form one hydrogen bond per molecule.

• Alkanoic acids (carboxylic acids): $-COOH$ group → can form two hydrogen bonds per molecule (via the carbonyl oxygen and hydroxyl hydrogen).

• Because of this, alkanoic acids often form dimers in the liquid state → stronger intermolecular forces → higher boiling points → lower volatility compared to alcohols.

Jamb 1990 past question 47