Final answer:
Acetone (CH₃-CO-CH₃) is falsely identified as an aldehyde; it is actually a ketone, as its carbonyl group is bonded to two carbon atoms, instead of at least one hydrogen as in aldehydes.
Step-by-step explanation:
False, acetone (CH₃-CO-CH₃) is not a three-carbon aldehyde; it is in fact a ketone. An aldehyde has a carbonyl group (C=O) bonded to at least one hydrogen atom, which is typically represented as -CHO. In the case of ethanal (acetaldehyde), the structure is CH₃CHO, clearly showing the aldehyde group. Acetone, on the other hand, has the carbonyl group bonded to two carbon atoms, thus conforming to the structure of ketones.
As such, the proper representation for an acetone molecule is CH₃-CO-CH₃, and it is also known as dimethyl ketone. The geometry around the carbon atom in a carbonyl group is trigonal planar, exhibiting sp² hybridization. This distinct molecular structure differentiates ketones from aldehydes and other carbonyl-containing compounds like carboxylic acids, esters, and amides.