18A.4

Question 1

What is phenol

Answer 1

a hydroxyl group attached to a benzene ring with similar properties to an aliphatic alcohol like ethanol.

Question 2

why do we expect that phenol would undergo electrophilic substitution

Answer 2

since it contains a benzene ring

Question 3

most aromatic compounds have

Answer 3

a benzene ring and a aliphatic part

Question 4

what is the difference between Bromination of benzene and Bromination of phenol

Answer 4

1. Bromination of benzene is slow and requires a catalyst and heating under reflux, while the Bromination of phenol works at room temp, with no catalyst
2. Bromination of phenol works with bromine water as it decolorizes it but benzene cant do that
3. the substitution in the Bromination of phenol is by 3 Br while benzene is just 1

Question 5

for the Bromination of phenol by bromine water what is observed

Answer 5

the decolorizing of the bromine water, and the formation of a white precipitate caused by the organic compound

Question 6

what is the reaction for the Bromination of phenol by bromine water

Answer 6

page 230

Question 7

what is the name of the white organic precipitate formed in the reaction of the Bromination of phenol by bromine water

Answer 7

2,4,6-tribromophenol

Question 8

how are the carbons number when naming a aromatic compound

Answer 8

clockwise with Oh being on the first carbon

Question 9

why is Bromination of phenol more readily than Bromination of Benzene

Answer 9

that is because
* the lone pair of electrons on the Pz-orbital on the oxygen in the OH group interacts with the delocalized pi-bond electrons in the ring.
* then the electron density above and below the ring of atoms increase, in a process called ‘activation’ since the molecule is now much more reactive towards electrophiles
*Bromine molecules, which are originally non-polar, are polarized as the approach the benzene ring. eventually the Br—Br bond is broken forming Br+ electrophile that attacks the benzene ring

Question 10

why is the process where the electron density of phenol is increased called activation

Answer 10

since the molecule is now much more reactive towards electrophiles

Question 11

what are the uses of phenol

Answer 11

• antiseptics surgery: as with time many other antiseptics were developed from phenol such as the product of the chlorination of phenol (2,4,6 trichlorophenol) known as antiseptic TCP

-manufacture of polymers

-manufacture of pharmaceuticals

Question 12

when benz is used in naming a organic compound it usually comes

Answer 12

after the other groups of the molecule