Which functional group is polar, containing an unsymmetrical distribution of charge between oxygen and hydrogen atoms?
Show answer & explanation
Correct answer: B
Explanation
The correct answer is option 2 i.e. Alcohols.
Alcohols. Alcohols contain the –OH (hydroxyl) functional group, which is polar due to the electronegativity difference between oxygen and hydrogen. Oxygen pulls the shared electrons closer, creating a partial negative charge on oxygen and a partial positive charge on hydrogen. This polarity allows alcohols to form hydrogen bonds, making them soluble in water and giving them relatively high boiling points.
Other options:
-
Amino group (–NH₂): Also polar but less so than hydroxyl, and it contains nitrogen instead of oxygen.
-
Carboxylic acids (–COOH): Contain both carbonyl and hydroxyl groups, making them strongly acidic and more reactive.
-
Esters (–COOR): Are less polar than alcohols because they lack a hydrogen atom bonded directly to oxygen.