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Alcohols
Alcohols have the function
group –OH
General formula: CnH2n+1OH
or CnH2n+2O
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Classification of alcohols
Primary alcohols – the C atom
with the OH group attached is
attached to only one other C
atom (OH on one end)
CH3CH2CH2CH2OH
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Secondary alcohol: the C atom
with the OH group attached is
attached to two other C atoms
CH3CH2CHOHCH3
Tertiary alcohol: the C atom with
the OH group attached is
attached to three other C atoms
CH3CH2C(CH3)OHCH3
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Properties of alcohols
1. M - MP and BP
2. Short chain alcohols are
miscible with water due to the
polar OH group but longer
chain alcohols are not miscible
with water
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3. Combustion – undergo
complete and incomplete
combustion
4. Oxidation of alcohols:
10 alcohol  aldehyde 
carboxylic acid O
O
CH3CH2OHCH3C –HCH3C-OH
Aldehyde step very quick
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Oxidation of alcohols
20 alcohols  ketones
13
30 alcohols  not oxidised
Chem
Oxidant:
Cr2O7- (orange)  Cr3+ (green)
12 Chemistry 2.5 organic chemistry CR 07