4.3 Alcohols + Phenols Flashcards
aromatic
containing benzene
aliphatic
does not contain benzene
what is a primary alcohol
-OH on a carbon which is attached to 0/1 other carbon
what is a Secondary alcohol
-OH on a carbon which is attached to 2 other carbon
what is a Tertiary alcohol
-OH on a carbon which is attached to 3 other carbon
what are the 2 methods of alcohol formation
- substitution from halogenoalkanes
- reduction of aldehydes, ketones or carboxylic acids
how to test for an alcohol
turns acidified H⁺/Cr₂O₇²⁻
orange –> green
how to test for phenol
turns Iron(III)chlorate
orange –> purple
how to test for a carboxylic acid
NaHCO₃
fizzing (CO₂)
how can alcohols be formed from halogenoalkanes
- reflux
- aqueous NaOH
- nuc sub (OH⁻ is the nucleophile)
what occurs when a primary alcohol is oxidised (+conditions)
aldehyde
potassium dichromate (dissolved in dilute sulphuric acid)
what occurs when a primary alcohol is FURTHER oxidised
carboxylic acid
what occurs when a secondary alcohol is oxidised
ketone
potassium dichromate (dissolved in dilute sulphuric acid)
what can be reduced to make a primary alcohol (+conditions)
aldehyde
NaBH₄
what can be reduced to make a secondary alcohol (+conditions)
ketone
aqueous NaOH
nuc add
alcohol + carboxylic acid =
ester + water
what happens when a tertary alcohol is oxidised
cannot be oxidised
how can carboxylic acids be reduced to make alcohols (+water)
LiAlH₄ - dissolved in ethoxyethane
dangerous, ∴ reduction of carbonyl is safer
nuc add
aromatic vs phenol
AROMATIC = OH bonded indirectly to benzene ring
PHENOL = OH bonded directly to benzene ring
what does distillation do
removes compounds with lower boiling points than the reactants
what are the 3 reactions of alcohols
- +halide
- +acid chloride
- +carboxylic acid
alcohol + halide =
halogenoalkane
why is alcohol + halide not often used
very slow, gives poor yield
what method is used for the chlorination of alcohol
HCl
ZnCl₂ catalyst
what is the problem with the chlorination of alcohol reaction
products difficult to separate.
1° and 2° = very slow
3° = quicker
what are the alternative reagent which speed up chlorination of alcohols
PCl₅ or SOCl₂
(poisonous gasses made)
what method is used for the bromination of alcohol
-KBr
-Conc H₂SO₄
(heat)
what method is used for the iodination of alcohol
- HI
- Reflux (+heat)
what is formed when an acid chloride (ethanoyl chloride) is added to an alcohol
ester + HCl
(HCl=misty fumes, violent)
why is ethanoyl chloride not used in the industry
not cost effective
acid chlorides = expensive
what 2 methods make esters
- alcohol + ethanoyl chloride
- alcohol + carboxylic acid
what is formed when a carboxylic acid is added to an alcohol
ester + H₂O
what are the conditions to make an ester from carboxylic acid + alcohol
- refluxed with conc H₂SO₄
- remaining acid neutralised with NaHCO₃
-separating funnel
-distilled
is phenol or benzene more reactive
phenol
is phenol or alcohol more acidic
phenol
why are phenols more acidic than alcohols
H⁺ is lost more easily in phenol
