11 public questions tagged with this topic.
Pentanal (CH₃CH₂CH₂CH₂CHO), a straight-chain aldehyde, has stronger dipole-dipole interactions than branched isomers like 2-methylbutanal, giving it the highest boiling point.
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Reactions due to α-Hydrogen - Aldol, Cannizzaro and Acidity of Carboxylic Acids
Boiling points depend on intermolecular forces: CH₃COOH (strong H-bonding) > CH₃CH₂OH (H-bonding) > CH₃CHO (dipole-dipole).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Reactions due to α-Hydrogen - Aldol, Cannizzaro and Acidity of Carboxylic Acids
Boiling points: Pentanoic acid (strong H-bonding) > Hexan-1-ol (H-bonding) > Hexanal (dipole-dipole).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Reactions due to α-Hydrogen - Aldol, Cannizzaro and Acidity of Carboxylic Acids
Boiling points: Pentanoic acid (strong H-bonding) > 2-Methylbutan-1-ol (H-bonding) > Pentanal (dipole-dipole).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Chemical Reactions - Reduction, Oxidation and Tests - Tollens, Fehling, Iodoform
The compound has a 5-carbon chain with a carboxylic acid group (pentanoic acid) and a double bond between C-3 and C-4: pent-3-enoic acid.
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Chemical Reactions - Reduction, Oxidation and Tests - Tollens, Fehling, Iodoform
The compound has a 4-carbon chain with a carboxylic acid group (butanoic acid) and a double bond between C-2 and C-3: but-2-enoic acid.
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Chemical Reactions - Reduction, Oxidation and Tests - Tollens, Fehling, Iodoform
Tollens' test is specific to aldehydes. Cyclohexanone (C₆H₁₀O), a ketone, does not reduce Tollens' reagent.
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Nomenclature, Structure and Preparation of Aldehydes and Ketones
Fehling’s solution oxidizes aliphatic aldehydes like ethanal (CH₃CHO) to form a red precipitate, but does not react with aromatic aldehydes like benzaldehyde (C₆H₅CHO).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Nomenclature, Structure and Preparation of Aldehydes and Ketones
Hexanal (CH₃CH₂CH₂CH₂CH₂CHO), a six-carbon aliphatic aldehyde, reduces Fehling’s solution to form a red Cu₂O precipitate.
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Nomenclature, Structure and Preparation of Aldehydes and Ketones
Reactivity decreases with steric hindrance. Di-tert-butyl ketone (bulky) < Acetone (less hindered) < Acetaldehyde (least hindered, aldehyde more reactive).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Nomenclature, Structure and Preparation of Aldehydes and Ketones
Reactivity: CH₃CHO (simple aldehyde) > (CH₃)₂CHCHO (branched aldehyde) > CH₃CH₂COCH₃ (ketone, steric hindrance).
Ref: NCERT Class 12 Chemistry > Chapter 12: Aldehydes, Ketones and Carboxylic Acids > Topic: Nomenclature, Structure and Preparation of Aldehydes and Ketones
