Aromatic

Question 1

Describe the structure of benzene:

Answer 1

Formula=C6H6
Each carbon atom forms single covalent bonds between the carbons on either side of it and a hydrogen. The final unpaired electron for each C is located in a p orbital which sticks above and below the plane of the ring, and these delocalised electrons form a ring.

Question 2

What is the length of the bonds in the benzene ring?

Answer 2

Lies between the length of a C-C bond and a C=C bond. 140pm

Question 3

What species does benzene attract?

Answer 3

Electrophiles, due to the ring being an area of high electron density

Question 4

What type of mechanism does benzene undergo with electrophiles?

Answer 4

Electrophilic addition- maintains the delocalised electrons ring so keeps the stability of benzene

Question 5

How do you form a nitrobenzene?

Answer 5

Warm benzene with concentrated nitric acid and concentrated sulfuric acid. This is an electrophilic substitution reaction.

Question 6

What is the equation to form a nitrite ion in a nitration reaction?

Answer 6

HNO3 + H2SO4 —> HSO4- + NO2+ + H2O

Question 7

What are Friedel-Crafts acylation reactions used for?

Answer 7

Used to add an acyl group to the benzene ring

Question 8

What are the reactants and products of a Friedel-Crafts acylation reaction?

Answer 8

Benzene and an acyl chloride forms a phenylketone and hydrochloric acid

Question 9

What is the reaction between an acyl chloride and AlCl3?

Answer 9

Acyl chloride + AlCl3 ——> carbocation + AlCl4-