Explanation

• Pyroligneous acid is a complex liquid obtained by the destructive distillation of wood in the absence of air.
• Its major components include acetic acid, methanol, acetone and other organic compounds.
• It is also known as wood vinegar.
• Methanol obtained from wood distillation was historically called wood alcohol.

Last verified on 02-11-2026

Explanation

• Ethyl acetate (CH₃COOC₂H₅) is an ester with a sweet, fruity smell.
• It is used as a flavouring agent in food products and beverages.
• It is commonly associated with pineapple-like fruity flavour.
• It is also widely used as an industrial solvent.

Last verified on 02-11-2026

Explanation

• Sodium acetate (CH₃COONa) undergoes decarboxylation when heated with soda lime (NaOH + CaO).
• The carboxyl group (–COO⁻) is removed, producing methane (CH₄).
• The reaction gives an alkane containing one carbon atom fewer than the original carboxylate salt.

Last verified on 02-11-2026

Explanation

• Glacial acetic acid is nearly pure, water-free acetic acid (CH₃COOH).
• It is called “glacial” because it freezes at approximately 16.6°C, forming ice-like crystals.
• Ordinary vinegar is a dilute aqueous solution of acetic acid, usually containing about 4–8% acetic acid.
• Acetic anhydride is a different chemical compound.

Last verified on 02-11-2026

Explanation

• Tollens' test is also called the silver mirror test.
• It is used to identify aldehydes because they reduce silver ions (Ag⁺) to metallic silver.
• A shiny silver coating forms on the inner surface of the test tube.
• The reagent contains ammoniacal silver nitrate, known as Tollens' reagent.

Last verified on 02-11-2026

Explanation

• Cannizzaro reaction is a self-oxidation-reduction (disproportionation) reaction.
• It occurs in aldehydes that do not contain an alpha-hydrogen atom, in the presence of a concentrated alkali.
• One aldehyde molecule is oxidized into a carboxylate salt, while another is reduced into an alcohol.
• Example: Benzaldehyde produces benzyl alcohol and sodium benzoate with concentrated NaOH.

Last verified on 02-11-2026

Explanation

• Ethyl alcohol (ethanol, C₂H₅OH) undergoes oxidation to form acetic acid (CH₃COOH).
• Potassium dichromate in acidic medium acts as a strong oxidizing agent.
• Acetaldehyde is an intermediate product during the oxidation of ethanol to acetic acid.
• Complete oxidation under suitable conditions produces acetic acid.

Last verified on 02-11-2026

Explanation

Explanation

• German chemist August Kekulé proposed the cyclic structure of benzene in 1865.
• He suggested that benzene (C₆H₆) consists of a six-carbon ring with alternating single and double bonds.
• The benzene ring is also known as the Kekulé structure.

Last verified on 02-11-2026

Explanation

• Ethene (C₂H₄) is an unsaturated hydrocarbon containing a carbon-carbon double bond.
• It decolourises cold, dilute alkaline KMnO₄ solution by undergoing oxidation.
• This test is known as Baeyer's test.
• It is used to detect unsaturation.

Last verified on 02-11-2026