Aromatic Chemistry

Question 1

State, in terms of its bonding, why benzene is more stable than
cyclohexa−1,3,5−triene

Answer 1

Electrons delocalised

Question 2

Explain your answers to part (i) and part (ii) in terms of the bonding in these
two dienes. (cyclohexa-1,3-diene and cyclohexa-1,4-diene)

Answer 2

-Proximity − for 1,3 C=C bonds are close together
-Proximity − for 1,3 C=C bonds are close together
-some extra stability for the 1,3- isome

Question 3

What is empirical formula?

Answer 3

The simplest whole number ratio of atoms present in a compound.

Question 4

What is the reducing reagent for the conversion of a nitrobenzene to a phenylamine?

Answer 4

-HCl

Question 5

What is the reducing reagent for the conversion of benzene to cyclohexane?

Answer 5

-H2

Question 6

What is the bond angle between the carbon atoms of benzene?

Answer 6

-120 degrees

Question 7

What is the bond angle between the carbon atoms of cyclohexane?

Answer 7

-109.5 degrees

Question 8

Why would a product be optically inactive?

Answer 8

-planar C=O bond
-the attack is equally likely from either side
-a racemic mixture is formed

Question 9

What is an arene?

Answer 9

-a molecule that contains a benzene ring

Question 10

What is the catalyst for acylation of a benzene ring?

Answer 10

-AlCl3

Question 11

What is necessary for the nitration of benzene?

Answer 11

-heat conc HNO3
-with H2SO4

Question 12

What is the bond length of C-C bonds in a benzene molecule?

Answer 12

-139pm