Benzene structure

Question 1

What is the shape of benzene?

Answer 1

Planar, regular hexagon with bond angles of 120 degrees.

Question 2

What is the bond length between CC bonds in benzene?

Answer 2

Intermediate length between carbon carbon single bond and carbon carbon double bond.

Question 3

What happens to the 4th electron in the P-orbital of each carbon in benzene?

Answer 3

It delocalises to form rings of electron density above and below the hexagon.

Question 4

What makes benzene more stable than the theoretical molecule cyclohexa-1,3,5-triene?

Answer 4

The delocalisation of the p electrons.

Question 5

Which of bond making and bond breaking is exothermic?

Answer 5

Bond making is exothermic. Bond breaking is endothermic.

Question 6

What does the enthalpy of hydrogenation of benzene being more positive than cyclohexa-1,3,5-triene tell you?

Answer 6

That benzene is more stable as more energy is taken in because breaking the bonds requires more energy (bond breaking is endothermic).

Question 7

Is benzene soluble in water? Why?

Answer 7

No, because it is nonpolar.