4.3 Alcohols + Phenols

Question 1

aromatic

Answer 1

containing benzene

Question 2

aliphatic

Answer 2

does not contain benzene

Question 3

what is a primary alcohol

Answer 3

-OH on a carbon which is attached to 0/1 other carbon

Question 4

what is a Secondary alcohol

Answer 4

-OH on a carbon which is attached to 2 other carbon

Question 5

what is a Tertiary alcohol

Answer 5

-OH on a carbon which is attached to 3 other carbon

Question 6

what are the 2 methods of alcohol formation

Answer 6

1. substitution from halogenoalkanes
2. reduction of aldehydes, ketones or carboxylic acids

Question 7

how to test for an alcohol

Answer 7

turns acidified H⁺/Cr₂O₇²⁻
orange –> green

Question 8

how to test for phenol

Answer 8

turns Iron(III)chlorate
orange –> purple

Question 9

how to test for a carboxylic acid

Answer 9

NaHCO₃
fizzing (CO₂)

Question 10

how can alcohols be formed from halogenoalkanes

Answer 10

• reflux
• aqueous NaOH
• nuc sub (OH⁻ is the nucleophile)

Question 11

what occurs when a primary alcohol is oxidised (+conditions)

Answer 11

aldehyde
potassium dichromate (dissolved in dilute sulphuric acid)

Question 12

what occurs when a primary alcohol is FURTHER oxidised

Answer 12

carboxylic acid

Question 13

what occurs when a secondary alcohol is oxidised

Answer 13

ketone
potassium dichromate (dissolved in dilute sulphuric acid)

Question 14

what can be reduced to make a primary alcohol (+conditions)

Answer 14

aldehyde
NaBH₄

Question 15

what can be reduced to make a secondary alcohol (+conditions)

Answer 15

ketone
aqueous NaOH

nuc add

Question 16

alcohol + carboxylic acid =

Answer 16

ester + water

Question 17

what happens when a tertary alcohol is oxidised

Answer 17

cannot be oxidised

Question 18

how can carboxylic acids be reduced to make alcohols (+water)

Answer 18

LiAlH₄ - dissolved in ethoxyethane

dangerous, ∴ reduction of carbonyl is safer

nuc add

Question 19

aromatic vs phenol

Answer 19

AROMATIC = OH bonded indirectly to benzene ring
PHENOL = OH bonded directly to benzene ring

Question 20

what does distillation do

Answer 20

removes compounds with lower boiling points than the reactants

Question 21

what are the 3 reactions of alcohols

Answer 21

1. +halide
2. +acid chloride
3. +carboxylic acid

Question 22

alcohol + halide =

Answer 22

halogenoalkane

Question 23

why is alcohol + halide not often used

Answer 23

very slow, gives poor yield

Question 24

what method is used for the chlorination of alcohol

Answer 24

HCl
ZnCl₂ catalyst

Question 25

what is the problem with the chlorination of alcohol reaction

Answer 25

products difficult to separate.
1° and 2° = very slow
3° = quicker

Question 26

what are the alternative reagent which speed up chlorination of alcohols

Answer 26

PCl₅ or SOCl₂
(poisonous gasses made)

Question 27

what method is used for the bromination of alcohol

Answer 27

-KBr
-Conc H₂SO₄
(heat)

Question 28

what method is used for the iodination of alcohol

Answer 28

• HI
• Reflux (+heat)

Question 29

what is formed when an acid chloride (ethanoyl chloride) is added to an alcohol

Answer 29

ester + HCl
(HCl=misty fumes, violent)

Question 30

why is ethanoyl chloride not used in the industry

Answer 30

not cost effective
acid chlorides = expensive

Question 31

what 2 methods make esters

Answer 31

• alcohol + ethanoyl chloride
• alcohol + carboxylic acid

Question 32

what is formed when a carboxylic acid is added to an alcohol

Answer 32

ester + H₂O

Question 33

what are the conditions to make an ester from carboxylic acid + alcohol

Answer 33

• refluxed with conc H₂SO₄
• remaining acid neutralised with NaHCO₃

-separating funnel
-distilled

Question 34

is phenol or benzene more reactive

Answer 34

phenol

Question 35

is phenol or alcohol more acidic

Answer 35

phenol