Phenols

Question 1

Explain the high boiling point of nitrophenol

Answer 1

Hydrogen bonding between individual molecules of para-nitrophenol

Question 2

Why is the boiling point in p-nitrophenol higher than in o-nitrophenol?

Answer 2

In o-nitrophenol, the nitro group and hydroxyl group resulting in intramolecular hydrogen bonding, preventing intermolecular hydrogen bonding

Question 3

Which is more acidic? Phenol (aromatic alcohol) or aliphatic alcohols?

Answer 3

Phenol, it forms a stable phenoxide ion when donating a proton

Question 4

Which is more stable? Phenoxide ions or alkoxide ions? Why?

Answer 4

Phenoxide ions because the negative charge is not confined to the oxygen atom, the aromatic ring can delocalize the negative charge of the oxygen within the carbons in the ring

Question 5

How many resonance structures of the phenoxide ion are there? How many atoms can the localize the charge of the phenoxide ions

Answer 5

There are 4 resonance structures and three different carbons can localize the charge in the ring in addition to the oxygen atom

Question 6

What is the effect of electron withdrawing groups on acidity of phenol?

Answer 6

Increases acidity

Question 7

What are the uses of phenols?

Answer 7

Antiseptics

Detergents

Pharmaceuticals

Dyes

Question 7

What is the effect of a nitro group as an electron withdrawing group on a phenoxide ion?

Answer 7

Stabilizes the phenoxide ion through resonance stabilization

Question 8

What is the effect of electron donating groups on the acidity of substituted phenols

Answer 8

Decreases acidity of substituted phenols, due to the donation of a lone pair of electrons destabilizing the negative charge on the oxygen

Question 9

What will phenol react to produce when oxidized?

Answer 9

Quinones

Question 10

What are quinones?

Answer 10

Para(1,4)-diketones

Question 11

What reagents can be used to produce the corresponding alkoxide and what is the biproduct?

Answer 11

Metals such as sodium, lithium and potassium

Biproduct- proton

Question 12

Name the 3 qualitative tests for phenol

Answer 12

1. Ferric Chloride test
2. Bromine-water test
3. Libermann test

Question 13

The ferric chloride test is usually used to differentiate between phenol and _______

Answer 13

Alcohol

Question 14

Describe how to conduct the ferric chloride qualitative test for phenol

Answer 14

Add 1 or 2 drops FeCl3 to 3 or 4 drops off phenol

Question 15

How will the Ferric Chloride test show positive for phenol?

Answer 15

Produces Diferric hexapentane (C6H5O)6Fe2 which gives a purple coloration

Question 16

What is the result of phenol in the bromine water test?

Answer 16

White precipitate is formed(2,4,6-tribomophenol)

Question 17

Aside from phenol, what are the reactants needed for Lieberman test

Answer 17

Solid NaNO2

Concentrated Sulfric acid

Heat

Question 18

What happens when Lieberman tests positive for phenol?

Answer 18

A green solution

Question 19

What are the qualitative tests for phenols.

Answer 19

1. Ferric Chloride
2. Bromine water
3. Lieberman

Question 20

What are the qualitative tests for phenols.

Answer 20

1. Ferric Chloride
2. Bromine water
3. Lieberman