Q.Carboxylic acids have higher boiling points than aldehydes, ketones and even alcohols of comparable molecular mass. It is due to their (NEET) a) more extensive association via van der Waals forces of attraction b) formation of a carboxylate ion c) formation of intramolecular H-bonding d) formation of intermolecular H-bonding

Step 1. Boiling point rises with the strength of intermolecular attraction between molecules -- weak van der Waals forces alone give the lowest boiling points, dipole-dipole interaction (as in aldehydes/ketones) gives somewhat higher ones, and genuine hydrogen bonding gives the highest of all (Section 12.4/12.11).

Step 2. A carboxylic acid's -COOH group can form TWO hydrogen bonds at once with a neighbouring -COOH -- donating its own O-H to one oxygen of the partner while accepting a hydrogen bond at its own carbonyl oxygen -- closing into a cyclic, doubly hydrogen-bonded DIMER, especially pronounced in the vapour phase. …

Compare the TYPE of intermolecular force available to each family (van der Waals only, versus dipole-dipole, versus true hydrogen bonding) and recognise that a carboxylic acid's doubled, cyclic hydrogen bon …

• Selecting 'intramolecular H-bonding' (option c) by a careless slip -- the hydrogen bonding responsible for a carboxylic acid's high boiling point is explicitly BETWEEN separate molecules (intermolecular), which is what raises the bo …