Aromatic Chemistry

Question 1

What is a conjugated system?

Answer 1

Alternating single and double bonds in its cyclic structure

Question 2

What reactions does benzene undergo? and what type of reaction is this?

Answer 2

-Forming alkyl halides
-Forming Alkanes
which are all addition reactions

Question 3

How can we form a akyl halide with benzene? (conditions)

Answer 3

Use 3Cl2 and UV light. 3CL2 so that 6 of the CL can be generated each to fit a ring so this would form a akyl chloride

Question 4

How can we form a alkane with benzene?

Answer 4

Ni catalyst and 300 degrees and 3H2 which would form 6 H atoms but because the double bond is broken this would case 6 other hydrogen atoms to be bonded to the ring because we’re forming an alkene

Question 5

What are all the substitute reactions of benzene?

Answer 5

aromatic nitration. aromatic sulfonation, formation of a diazonium salt, sandmeyer reactions, azo coupling reactions and all friedel craft reactions substitute reactions of benzene

Question 6

What are the condtions for aromatic nitration? and what is formed?

Answer 6

conc HNO3 and conc H2SO4/ 50 degrees

jus NO added to the ring

Question 7

How can we do dinitiration? where 2 NO2 is added?

Answer 7

using conc H2SO4/ conc HNO3 under 100 degrees

Question 8

What are the conditions for Aromatic sulfonation? and what is formed

Answer 8

Conc H2SO4 under 3 reflux
Benzenesulfonic acid

Question 9

How can we generate a Diazonium salt?

Answer 9

Generated by aromatic amine with nitrous acid (HNO2)

Question 10

What are the conditions to form a dianoium salt?

Answer 10

NANO2/ HCL at 5 degrees OR H2SO4 and NANO2 at 5 degrees

Question 11

What are the two reactions a diazonium salt can undergo?

Answer 11

Sandmeyer reaction and azo coupling reaction

Question 12

Using the sandmeyer reaction,how can we generate benzene from a diazonium salt?

Answer 12

react the salt with H3PO2

Question 13

Using the sandmeyer reaction,how can we generate phenol from a diazonium salt?

Answer 13

react it with H20/HEAT

Question 14

Using the sandmeyer reaction,how can we generate CHOLOROBENEZENE from a diazonium salt?

Answer 14

react it with CuCl, and conc HCL under heat

Question 15

Using the sandmeyer reaction,how can we generate bromobenzene from a diazonium salt?

Answer 15

react it with CuBr and conc HBr AND heat

Question 16

Using the sandmeyer reaction,how can we generate iodobenzene from a diazonium salt?

Answer 16

react it with Ki and heat

Question 17

Using the sandmeyer reaction,how can we generate nitrile from a diazonium salt?

Answer 17

react it with NaCN, CuCN and heat

Question 18

How can we form a azo dye?

Answer 18

reacting the salt with (aromatic alcohol) phenol or phenylamine

Question 19

Rank ortho, meta and para positions in terms of reactivity and where does the diazonium salt react with?

Answer 19

1. ortho, 2.meta and 3. para (here)

Question 20

What are all the Friedel- crafts reacction catalyst?

Answer 20

ALCL3, ALBr3, FeCl3, FeBr2, Fe (s)/Cl2 (g), Fe (s)/ Br2 (l)

Question 21

What are the condtions to add a akyl group to a aromatic ring

Answer 21

FEB3 under 40 degrees and the product is hydrogen and B

Question 22

What are the conditions for friedel craft accylation (adding acyl) group R-C=O to an aromatic ring?

Answer 22

AlCl3 under 40 degrees the productwill be Hydrogen and CL

Question 23

What are the condtions to introduce a halide atom to an aromatic ring?

Answer 23

Fe (s)/ CL2 (g) under DARk product is H and the halide
must be done without light

Question 24

What will happen if the halogenation reaction occurs in the presence of light?

Answer 24

Addition of halogen and halogen substitution on any alkyl side chain which means the enter ring will get the halogen

Question 25

What will happen to any side chains when they are oxidized? eg with KMnO4

Answer 25

Aromatic rings are usually resisant to oxidation reactions but any alkyl chainspresent will be oxidized to a carboxlyic acid, Benzoic acid is always formed.