Which of the following is incorrect regarding resonance?

Options

A. The canonical forms have no real existence.
B. The molecule exists for a certain fraction of time in one canonical form and for other fractions of time in other canonical forms.
C. There is no such equilibrium between the canonical forms as we have between tautomeric forms (keto and enol) is tautomerism.
D. The molecule as such has a single structure which is the resonance hybrid of the canonical forms and which cannot as such be depicted by a Lewis structure.

Answer

B

Explanation

A molecule or polyatomic ion for which two or more Lewis formulas with the same arrangement of atoms can be drawn to describe the bonding is said to exhibit resonance. The different Lewis structures drawn are resonance structures of the molecule or ion. The relationship among them is indicated by the double-headed arrow `iff`. This symbol does not mean that the molecule or ion flips back and forth among different Lewis structures. The true structure can be described as an average, or hybrid, of the three.