Which statements about resonance are true?
I. Resonance hybrids do occur because a compound changes back and forth between two or more resonance structures.
II. Resonance structures do differ in the arrangement of electrons but not in the arrangement of atoms.
III. Resonance hybrids contain delocalized electrons.
IV. Resonance structures for a given compound always contribute equally to the resonance hybrid.
V. Resonance structures occur when there are two or more valid Lewis structures for a given compound.
VI. Resonance hybrids are a composite of resonance structures.
A) I, II, V, VI
B) II, III, IV, VI
C) II, IV, V, VI
D) II, III, V, VI

Question

Quizplus · Accepted Answer

Resonance structures represent different ways of drawing the same molecule, showing different distributions of electrons but not different placements of atoms, making statement II true. Resonance hybrids indeed contain delocalized electrons, which is what statement III describes. Statement IV is incorrect because not all resonance structures contribute equally to the hybrid; their contribution depends on the stability of each structure. Statement V is accurate as resonance structures are indeed different valid Lewis structures for the same molecule, showing different electron distributions. Finally, statement VI is correct because a resonance hybrid is a blend or composite of all the resonance structures, representing the molecule more accurately than any single resonance structure.

Which Statements About Resonance Are True