Answer to Question #150052 in Organic Chemistry for Faizan

Question

. How Formal Charge can be used to affirm the presence of resonance structure
in NO3^-1 molecule

Answer 1

Resonance structures is a scientific method to distinguish between all identically related atoms (in this case the three oxygen atoms) by symmetry and structure.

The structure can be observed, such that the oxygen atoms will vary in their distance from the nitrogen during the passage of an infrared pulse in such a manner as to cause the creation of a temporary electrical dipole, which can be sensed by the electric vector component of radiation and an exchange of energy is allowed. This can be represented by two of the oxygen atoms being closer to the N at that instant, which can be visualized as having less bonding to N than the other two and carrying the -ve charge of the unit as a consequence. This is then the “resonance” form, and must be carried by all three of the O atoms because they are indistinguishable.

In the resonance structure, as the negative charges move around the three O atoms in time with the IR radiation electric field, it can be imagined how the observed interaction can occur.