Aromatics

Question 1

Explain bonding of benzene

Answer 1

Each C has 3 covalent bonds. Spare e- in a p orbital overlap, delocalisation

Question 2

Explain the shape of benzene

Answer 2

Planar, hexagon/ 6 C ring/ 120° angle, C-C bonds in equal length

Question 3

What does it mean if double bonds are closer together?

Answer 3

There’s some delocalisation which increased stability. Lower delta H

Question 4

How do you name benzene molecules?

Answer 4

benzene is root. phenyl is prefix

Question 5

TNT name and molecular formula

Answer 5

2-methyl-1,3,5-trinitrobenzene
C6H2(NO2)3(CH3)

Question 6

What are the two electrophiles?

Answer 6

nitronium ion N+O2
acylium ion RCO+

Question 7

What is the name of the mechanism?

Answer 7

Electrophilic substitution

Question 8

Mechanism

Answer 8

Question 9

What are the catalysts needed to form nitrobenzene?

Answer 9

concentrated H2SO4 and concentrated HNO3

Question 10

Equation to make N+O2

Answer 10

Question 11

Why is methylbenzene more reactive than benzene? What does it mean for the reaction?

Answer 11

methylbenzene is a tertiary carbon so has a bigger positive inductive effect and is more e- rich. A lower temp can be used

Question 12

What is the length of bonds from the smallest to largest?

Answer 12

C=C , benzene , C-C

Question 13

How does the catalyst regenerate in the nitrobenzene reaction?

Answer 13

HSO4- + H+ —> H2SO4

Question 14

What’s the delta H of benzene like compared to other molecules?

Answer 14

Lower than expected because it’s more stable

Question 15

What catalyst is used to form a phenylketone?

Answer 15

AlCl3

Question 16

Reaction for RC+O

Answer 16

RCOCl + AlCl3 —> AlCl4- +. R C+O

Question 17

How is the catalyst for phenylketones regenerated?

Answer 17

AlCl4- + H+ —> AlCl3 + HCl