Question

3) for one resonance structure of a nitrate(NO3-) provide the:
a) Lewis structure

b) formal charge on each atom

c)name of the electro pair(electron domain) geometry

d) hybridization of the central atom

e)name of the molecular geometry (shape)

Answer 1

Resonance structures of nitrate ion can be shown as given below:

Nitrate ion has one nitrogen atom bonded to three oxygen atoms. Three resonating structures of nitrate ions can be shown as follows:

a) Lewis structure of nitrate ion can be shown as follows:

b) Formal charge on each atom can be calculated using following expression:

Formal charge = valence electrons - nonbonding electrons - (bonding electrons/2)

Formal charge on nitrogen = 5 - 0 - (8/2) = +1

Formal charge on single bonded oxygen = 6 - 6 - (2/2) = -1

Formal charge on double bond oxygen = 6 -4 - (4/2) = 0

c) Electron pair geometry of nitrate ion:

Nitrate ion has central nitrogen atom with zero loan pair of electrons and three bonding groups (oxygen atoms) connected to nitrogen. Thus, electron pair geometry of nitrate ion is trigonal planar.

d) Hybridization of central atom:

Central nitrogen atom is SP² hybridized. Three SP² hybrid atoms forms bond with three oxygen atoms.

e) Molecular geometry of nitrate ion:

The central nitrogen atom is SP2 hybridized. Hence, the molecular shape of nitrate ion is trigonal planar.