Alcohols
Alcohols connect to haloalkanes through alcohol-halogenation and haloalkane hydrolysis, and also feed oxidation, dehydration and ester routes.
- Functional group
- C-OH
Overview
O-H functional group used in oxidation, substitution and ester chemistry.
Alcohols connect to haloalkanes through alcohol-halogenation and haloalkane hydrolysis, and also feed oxidation, dehydration and ester routes.
Identifiers
- Functional group
- C-OH
Chemical identifiers
- SMILES
- CCO
Diagnostic tests
acidified dichromate oxidation test
- Reagent
- acidified K2Cr2O7(aq)
- Conditions
- Add aqueous potassium dichromate(VI), acidified with dilute sulfuric acid, to the sample and warm gently in a water bath.
- Positive observation
- the orange solution turns green
- Negative observation
- the solution remains orange
- Interpretation
- A colour change supports the presence of a primary or secondary alcohol because it is oxidised under these conditions.
- Scope
- Primary and secondary alcohols give the colour change; tertiary alcohols normally do not.
- Limitations
- Aldehydes and other reducing compounds also turn acidified dichromate green; tertiary alcohols can give a negative result.
- Evidence
- textbook core
Related compounds
- Ethanol
Ethanol is a molecule-level primary alcohol within the alcohol family.
- Methanol
Methanol is an organic compound with the molecular formula CH4O.
- Propan-1-ol
A primary alcohol linking hydrogen bonding, aldehyde formation and further oxidation.
- Propan-2-ol
A secondary alcohol that oxidises to propanone.
- Butan-1-ol
Butan-1-ol is an organic compound with the molecular formula C4H10O.
- Butan-2-ol
Butan-2-ol is an organic compound with the molecular formula C4H10O.
- 2-Methylpropan-1-ol
A branched primary alcohol whose oxidation retains the carbon skeleton.
- 2-Methylpropan-2-ol
A tertiary alcohol that contrasts with primary and secondary oxidation examples.
- Pentan-1-ol
Pentan-1-ol is an organic compound with the molecular formula C5H12O.
- Hexan-1-ol
Hexan-1-ol is an organic compound with the molecular formula C6H14O.
- Octan-1-ol
Octan-1-ol is an organic compound with the molecular formula C8H18O.
- Cyclohexanol
Cyclohexanol is an organic compound with the molecular formula C6H12O.
- Benzyl alcohol
A primary alcohol whose CH2OH group is attached to a phenyl ring.
- 2-Phenylethanol
2-Phenylethanol is an organic compound with the molecular formula C8H10O.
- Glycerol
Propane-1,2,3-triol, a three-hydroxyl building block of fats and oils.
Connected reactions
- Chlorination: Alcohols → Chloroalkanes
Alcohols can be converted into chloroalkanes to create a better leaving group for downstream substitution.
- Chlorination with thionyl chloride: Alcohols → Chloroalkanes
Thionyl chloride converts alcohols into chloroalkanes with sulfur dioxide and hydrogen chloride as by-products.
- Bromination: Alcohols → Bromoalkanes
Bromide and acid conditions convert alcohols into bromoalkanes.
- Iodination: Alcohols → Iodoalkanes
Iodine and red phosphorus conditions convert alcohols into iodoalkanes.
- Hydrolysis: Chloroalkanes → Alcohols
The C-Cl bond can be displaced by hydroxide to form an alcohol.
- Hydrolysis: Bromoalkanes → Alcohols
The C-Br bond can be displaced by hydroxide to form an alcohol.
- Hydrolysis: Iodoalkanes → Alcohols
The C-I bond can be displaced by hydroxide to form an alcohol.
- Oxidation: Alcohols → Aldehydes
Controlled oxidation of a primary alcohol gives an aldehyde.
- Oxidation: Alcohols → Ketones
Oxidation of a secondary alcohol gives a ketone.
- Oxidation: Alcohols → Carboxylic acids
Full oxidation of a primary alcohol gives a carboxylic acid.
- Hydration: Alkenes → Alcohols
Catalytic hydration converts alkenes into alcohols.
- Dehydration: Alcohols → Alkenes
Dehydration converts alcohols into alkenes.
- Esterification co reactant: Alcohols → Esters
Alcohols combine with carboxylic acids to form esters.
- Hydrolysis co product: Esters → Alcohols
Hydrolysis of an ester also regenerates the alcohol component.
- Complete combustion: Alcohols → Carbon dioxide
Alcohols burn completely in excess oxygen to form carbon dioxide and water.
References
- Pearson Edexcel International Advanced Level Chemistry Practical GuidePearson Education Limited · Pearson qualifications · 2018
Official Pearson practical guidance for organic qualitative tests, including bromine water, acidified dichromate, silver nitrate, carbonyl reagents and the iodoform reaction.
- PubChem Compound Summary for EthanolNational Center for Biotechnology Information · PubChem · 2026
Used for stable identifiers and basic compound metadata.
- PubChem Compound Summary: Methanol (CID 887)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Propan-1-ol (CID 1031)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Propan-2-ol (CID 3776)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Butan-1-ol (CID 263)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Butan-2-ol (CID 6568)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: 2-Methylpropan-1-ol (CID 6560)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: 2-Methylpropan-2-ol (CID 6386)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Pentan-1-ol (CID 6276)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Hexan-1-ol (CID 8103)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Octan-1-ol (CID 957)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Cyclohexanol (CID 7966)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Benzyl alcohol (CID 244)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: 2-Phenylethanol (CID 6054)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.
- PubChem Compound Summary: Glycerol (CID 753)National Center for Biotechnology Information · PubChem
Identity, molecular formula, molecular weight and aliases retrieved via PUG REST on 2026-09-08.