Question

The correct properties of aldehydes and ketones are:

• A. 1 and 2
• B. 2 and 3
• C. 1 and 4
• D. 2 and 4

Answer 1

The correct option is A 1 and 2

The properties of aldehydes and ketones are:
(1) They are polar in nature.
the carbonyl group C = O is polar in nature due to electronegativity difference between C and O atoms.
(2) They can form hydrogen bonds in water
Aldehydes and ketones contain polar carbonyl oxgen atom which can form hydrogen bonds with H atom of the water molecule.
(3) Aldehydes and ketones cannot form hydrogen bonds with themselves as H atom is not attached to electronegative O atom. It is attached to C atom.
(4)The polar and stronger carbon-to-oxygen double bond result in increase dipole-dipole interaction which causes aldehydes and ketones to have higher boiling points than those of alkanes of similar molecular masses but lower than those of comparable alcohols that engage in intermolecular hydrogen bonding.
Hence option (a) is correct.