[georgina_009]

Which of the following statements is not true about the structure of benzene?



  a. The carbon-carbon bonds are all the same length   
  b. The structure rapidly transforms between two resonance forms   
  c. The ring of six carbon atoms is planar   
  d. The structure is a hybrid of two significant resonance forms   

[squeak]

Your thoughts? 

[Padfoot]

b) and d) contradict each other.  Which one is true, which one is false?

http://en.wikipedia.org/wiki/Benzene

[Siddy]

A and C are correct.

What the question is demonstrating is the meaning behind the way we illustrate the benzene molecule.
Because you can not draw the bond arrangement, we either draw a circle in the hexagon or double bonds at every other carbon. This does not mean the bond strengths are different between carbons or that the lengths are different.

[squeak]

B and D certainly do contradict one another and for the simple reason that B is wrong and D is correct.

The two Kekule structures are not different i.e. to say you cannot distinguish between them, isolate them or tell one apart from the other as if they were two and so on.

http://en.wikipedia.org/wiki/Resonance_structure