Hydrogen bonding plays a central role in which of the following phenomena?

Options

A. Ice floats in water
B. Higher Lewis basicity of primary than tertiary amines in aqueous solutions
C. Formic acid is more acidic than acetic acid
D. Dimersation of acetic acid in benzene .

Answer

A, B, D

Explanation

Ice has cage -like structure in which each water molecule is surroundded by four water molecules tetrahedrally through hydrogen bonding due to this density if ice is less than water and it floats in water
`R -NH_(2)+H-OHhArrR-underset((I))overset(o+)NH_(3)+OHbar`
`(R)_(3)N+H-OHhArr(R)_(3)-overset(o+)(NH_(3)) +OHbar`
The cation (I) is more stabilized through hybdrogen bonding than cation (II) `So, R -NH_(2)` is better base than `(R )_(3)N` in
`HCOOH ` is stronger acid than `CH_(3)COOH` due to inductive effect and not due to hydrogne bonding
of `CH_(3)` group intensifies negative charge on acetate ion and make that ion unstable
(d) Acetic acid dimerizes in benzene through intermolecualr hydrogen bonding .
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