An aromatic hydrocarbon :?

Question

A - possesses the sulfur heteroatom.
B - contains a ring of double and single bonds.
C - necessarily has an odor.
D - can never be unsaturated.

Answer 1

B: all the aromatic compounds contain at least one benzene-like portion in their structure. Benzene is cyclohexatriene (C6H6), and all the other aromatics are of a like nature.

Answer 2

A - It can. For example thiopene (a 5 member ring with 1 sulfur) or dithiane (6 member ring with 2 sulfur)

B - Absolutely false. There are no truely distinct bonds in an aromatic ring. The bond lengths are actually between that of a single and double bond. The electrons are delocalized in the ring.

C - Probably not true. The name "aromatic" came about because Michael Faraday discovered benzene in oil gas and he assumpted that it was the source of the odor he smelled, while it probably was not.

D - It must be unsaturated. If the ring is saturated (since benzene rings contain 3 degrees of unsaturated), the aromaticity is lost. Aromatics can be saturated with hydrogen, on teh appropriate catalyst (Rh, for example)

Answer 3

I think C is the most correct. The specificity of the human olfactory sense should nearly always detect an aromatic compound.

B is correct if resonance structures are drawn, but resonance structures are just a visual mechanism that allows us humans to understand the reactivity of aromatic functional groups. The delocalization of the pi electron clouds in an aromatic ring is not really alternating double and single bonds, but a completely different structure.

Answer 4

An aromatic hydrocarbon is a ring structure that has an odor. that makes both B and C correct.

Answer 5

B

Most important examples of aromatic hydrocarbons are benzene and its derivatives.

Answer 6

Indeed B.
Aromatic hydrocarbons are ring structures.

Answer 7

b

Answer 8

B

Answer 9

B.