Question

Benzene behaves differently from a hydrocarbon which simply contains three C=C bonds in that the latter would be expected to react much more readily with __________.

A) H2
B) Cl2
C) Br2
D) HCl
E) all of the above

Answer 1

Benzene is stable due to its delocalized electrons and does not readily undergo addition reactions unlike alkenes. A hydrocarbon with three C=C bonds would readily react with all substances mentioned; hydrogen, chlorine, bromine, and hydrogen chloride, unlike benzene.

Step-by-step explanation:

Benzene behaves differently from a hydrocarbon which simply contains three C=C bonds because it exhibits a special kind of stability due to its delocalized pi electrons in a ring structure. This stability arises from the alternating single and double C-C bonds that form a delocalized electron system across the benzene ring.

Therefore, benzene does not readily undergo addition reactions like alkenes, which readily react with substances such as hydrogen, halogens, and hydrogen halides. Consequently, a hydrocarbon with three C=C bonds would be expected to react much more readily with all of the above options offered: A) H2 (hydrogen), B) Cl2 (chlorine), C) Br2 (bromine), and D) HCl (hydrogen chloride).

The molecular formula of benzene, C6H6, implies a high degree of unsaturation similar to alkenes, but due to the unique aromatic ring structure of benzene, it displays remarkable inertness towards addition reactions. However, under extreme conditions involving high temperatures and pressures with catalysts, benzene can slowly add molecules such as hydrogen to form cyclohexane.