ATAR Chemistry Unit 4
Practical Investigation – Identification of
Unknown Organic Compounds
Introduction
The identification and characterisation of substances is an important aspect of organic chemistry. In
this experiment, several tests will be carried out to allow for the identification of eight unknown
organic compounds. These tests include simple qualitative tests such as identifying colour and smell,
as well as testing for solubility, reactivity, and boiling points. The compounds to be determined will be
cyclohexane, cyclohexene, ethanol, ethanoic acid, butan-1-ol, butan-2-ol, 2-methylpropan-2-ol, and
methyl benzene (toluene).
Planning
Hexane Hexene
• Formula: C6H14 or CH3(CH2)4CH3 • Formula: C6H12 or CH2=CH(CH2)3CH3
• Functional group: alkane • Functional group: alkene
• Solubility in water: insoluble • Solubility in water: insoluble
• Molecular weight: 86.18 • Molecular weight: 84.16
• Boiling point: 69°C • Boiling point: 63°C
• Appearance: clear, colourless liquid • Appearance: clear, colourless liquid
• Odour: petroleum-like odour • Odour: petroleum-like odour
Ethanol Ethanoic acid
• Formula: C2H6O or CH3CH2OH • Formula: C2H4O2 or CH3COOH
• Functional group: alcohol (primary) • Functional group: carboxylic acid
• Solubility in water: soluble • Solubility: soluble
• Molecular weight: 46.07 • Molecular weight: 60.05
• Boiling point: 78°C • Boiling point: 118°C
• Appearance: clear, light-orange liquid • Appearance: clear, colourless liquid
• Odour: strong, vinous odour • Odour: strong vinegar odour
Butan-1-ol 2-methylpropan-2ol
• Formula: C4H10O or CH3(CH2)3OH • Formula: C4H10O or CH3CHOHCH2CH3
• Functional group: alcohol (primary) • Functional group: alcohol (tertiary)
• Solubility in water: insoluble • Solubility in water: soluble
• Molecular weight: 74.12 • Molecular weight: 74.12
• Boiling point: 118°C • Boiling point: 82°C
• Appearance: clear, colourless liquid • Appearance: clear, light-yellow liquid
• Odour: strong, vinous odour • Odour: mothball-like odour
Butan-2-ol Methyl benzene
• Formula: C4H10O or CH₃CHCH₂CH₃ • Formula: C7H8
• Functional group: alcohol (secondary) • Functional group: benzene
• Solubility in water: soluble • Solubility in water: insoluble
• Molecular weight: 74.12 • Molecular weight: 92.14
• Boiling point: 100°C • Boiling point: 110°C
• Appearance: clear, colourless liquid • Appearance: clear, colourless liquid
• Odour: strong, vinous odour • Odour: sharp, sweet odour
Practical Investigation – Identification of
Unknown Organic Compounds
Introduction
The identification and characterisation of substances is an important aspect of organic chemistry. In
this experiment, several tests will be carried out to allow for the identification of eight unknown
organic compounds. These tests include simple qualitative tests such as identifying colour and smell,
as well as testing for solubility, reactivity, and boiling points. The compounds to be determined will be
cyclohexane, cyclohexene, ethanol, ethanoic acid, butan-1-ol, butan-2-ol, 2-methylpropan-2-ol, and
methyl benzene (toluene).
Planning
Hexane Hexene
• Formula: C6H14 or CH3(CH2)4CH3 • Formula: C6H12 or CH2=CH(CH2)3CH3
• Functional group: alkane • Functional group: alkene
• Solubility in water: insoluble • Solubility in water: insoluble
• Molecular weight: 86.18 • Molecular weight: 84.16
• Boiling point: 69°C • Boiling point: 63°C
• Appearance: clear, colourless liquid • Appearance: clear, colourless liquid
• Odour: petroleum-like odour • Odour: petroleum-like odour
Ethanol Ethanoic acid
• Formula: C2H6O or CH3CH2OH • Formula: C2H4O2 or CH3COOH
• Functional group: alcohol (primary) • Functional group: carboxylic acid
• Solubility in water: soluble • Solubility: soluble
• Molecular weight: 46.07 • Molecular weight: 60.05
• Boiling point: 78°C • Boiling point: 118°C
• Appearance: clear, light-orange liquid • Appearance: clear, colourless liquid
• Odour: strong, vinous odour • Odour: strong vinegar odour
Butan-1-ol 2-methylpropan-2ol
• Formula: C4H10O or CH3(CH2)3OH • Formula: C4H10O or CH3CHOHCH2CH3
• Functional group: alcohol (primary) • Functional group: alcohol (tertiary)
• Solubility in water: insoluble • Solubility in water: soluble
• Molecular weight: 74.12 • Molecular weight: 74.12
• Boiling point: 118°C • Boiling point: 82°C
• Appearance: clear, colourless liquid • Appearance: clear, light-yellow liquid
• Odour: strong, vinous odour • Odour: mothball-like odour
Butan-2-ol Methyl benzene
• Formula: C4H10O or CH₃CHCH₂CH₃ • Formula: C7H8
• Functional group: alcohol (secondary) • Functional group: benzene
• Solubility in water: soluble • Solubility in water: insoluble
• Molecular weight: 74.12 • Molecular weight: 92.14
• Boiling point: 100°C • Boiling point: 110°C
• Appearance: clear, colourless liquid • Appearance: clear, colourless liquid
• Odour: strong, vinous odour • Odour: sharp, sweet odour
