Question

Which is FALSE about the "true structure" of a molecule vs individual resonance forms? (Assume there are two or more plausible resonance forms)

Group of answer choices

1. The true structure is not exactly the same as any of the resonance forms.

2. The true structure is closest to the "best" resonance structure.

3. We can usually discern from examining the individual resonance forms which is qualitatively better or worse than the other (or if they are identical).

4. The true structure of a molecule vibrates back and forth from among the possible resonance forms.

Answer 1

2. is False.

Because the true structure is not the closest to the best resonance structure.

But the true structure is inetermediate of all possible resonance structures. It is called resonance hybrid.

Remaining statements are correct regarding resonance structures and true structure.

True statements:

1. The true structure is not exactly the same as any of the resonsce forms because the true structure is intermediate of all the possible resonance forms.

3. We can usually discern from examining the individual resonance forms which is qualitatively better or worse than the other.

Among the resonance forms,

One with no charge separation is more stable.

If there is charge separation, one with less charge separation is more stable.

If there is charge separation, one with negative charge on more electronegative atom is more stable.

4. The structure of a molecule vibrates back and forth among the possible resonance forms due to delocalisation of pi electrons which is main responsible for the existance of resonance forms.