Q10.11P - Chemistry: Molecular Nature Of Matter And Change

Question

Draw Lewis structures of all the important resonance forms of

(a)  ${{\mathbf{N}}_3}^{-}$

(b)  ${{\mathbf{NO}}_2}^{-}$

Step-by-Step Solution

Answer

The resonance hybrid form of 

a. ${{\mathbf{N}}_3}^{-}$ = Linear shape

b. ${{\mathbf{NO}}_2}^{-}$ = bent shape

 

Lewis Structure

A Lewis structure can be defined as the basic structure of a molecule which used valence electron of each atom involved. In Lewis’s structure, the least electronegative atom will be the central atom.

Explanation

N belongs to group 15 having 5 electrons in the valence that requires give or take 3 electrons to fulfil its octet, In Lewis’s structure, the N-atom needs 3 electrons which will be provided by the other 2 N-atom. Both N-atom provides 2 electrons to the one N-atom and there is the movement of electrons from one N-atom to another N-atom. There is a movement of positive charge over N-atom and there is a positive charge over N-atom to fulfil its octet.

                             

Simplification

N belongs to group 15 having 5 electrons in the valence required to give or take 3 electrons to fulfil its octet, O-atom belongs to group 16 having 6 electrons in the valence shell and requires 2 electrons to fulfil the octet. In Lewis’s structure, the N-atom needs 3 electrons which will be provided by the 2 O-atom. The O-atom is more electronegative than N-atom and becomes negatively and positively charged respectively. There is the movement of electrons from one O-atom to another O-atom. The N-atom acquire a positive charge and there is the movement of the negative electron over the electronegative O-atom.