Rank the following in order of decreasing importance as a contributing resonance structure to the molecular structure of acetone, CH₃COCH₃ (more important less important) A)1 2 3 B)1 3 2 C)2 1 3 D)3 1 2

Question

Rank the following in order of decreasing importance as a contributing resonance structure to the molecular structure of acetone, CH₃COCH₃ (more important > less important) A)1 > 2 > 3 B)1 > 3 > 2 C)2 > 1 > 3 D)3 > 1 > 2

Quizplus · Accepted Answer

The carbonyl group (C=O) is the most important contributing resonance structure of acetone because it has the greatest electron density and is the most stable. The resonance structures with double bonds between the carbon and oxygen atoms (1 and 3) are therefore more important than the structure with a double bond between carbon and one of the methyl groups (2). Therefore, the correct ranking is 1 > 3 > 2, which is best represented by choice B.

Rank the Following in Order of Decreasing Importance as a Contributing