JEE Advanced 2014 Paper 1

(A) Ice has cage-like structure in which each water molecule is surrounded by four other water molecules tetrahedrally through hydrogen boding, due to this density of ice is less than water and it floats in water.

(R)3N+H−OH⇌(R)3−

⊕ N H

(II)

+OH−
The cation (I) more stabilized through hydrogen boding than cation (II) . So,R−NH2 is better base than (R)3N in aqueous solution.
(C) HCOOH is stronger acid than CH3COOH due to inductive effect and not due to hydrogen bonding.
(D)Acetic acid dimerizes in benzene through intermolecular hydrogen bonding.