Question

Hydrogen bonding plays a central role in the following phenomena: 

(A) Ice floats in water. 

(B) Higher Lewis basicity of primary amines than tertiary amines in aqueous solutions. 

(C) Formic acid is more acidic than acetic acid. 

(D) Dimerisation of acetic acid in benzene.

Answer 1

(A) Ice floats in water.  

(B) Higher Lewis basicity of primary amines than tertiary amines in aqueous solutions. 

(D) Dimerisation of acetic acid in benzene.

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.