C27 - Aromatic chemistry

Question 1

What is the molecular formula for benzene?

Answer 1

C6H6

Question 2

What is the empirical formula for benzene?

Answer 2

CH

Question 3

What does benzene form when it undergoes hydrogenation with a nickel catalyst?

Answer 3

Cyclohexane

Question 4

What happens with benzene in bromine water?

Answer 4

It does not decolourise and the solution remains orange

Question 5

What is the issue of bond lengths in benzene?

Answer 5

All bonds were of an equal length – 0.140 nm; somewhere in between that which would be expected for a single and a double bond

Question 6

What are the internal angles in benzene?

Answer 6

120 degrees

Question 7

What is the layout of electrons in benzene?

Answer 7

Each carbon has a p-orbital above and below the ring forming a continuous pi bond above and below the ring. Each carbon uses three of its outer electrons to form three sigma bonds to two other carbon atoms, and one hydrogen atom

Question 8

What are arenes?

Answer 8

Arenes are aromatic hydrocarbons that contain one or more benzene rings

Question 9

How is a nitronium ion formed?

Answer 9

H2SO4 is reacted with HNO3
NO2+ , HSO4 - and H2O are formed

Question 10

What removes the chlorine from an acid chloride at the start of a Friedl-craft reaction?

Answer 10

AlCl3
[AlCl4]- is formed