MCQs – Aldehydes, Ketones & Carboxylic Acids

1. Which of the following gives a positive silver mirror test (Tollen’s test)?
a) Formaldehyde
b) Acetone
c) Benzophenone
d) Acetophenone

2. Which of the following does not give Fehling’s test?
a) Formaldehyde
b) Acetaldehyde
c) Glucose
d) Benzaldehyde

3. The most reactive aldehyde towards nucleophilic addition is:
a) HCHO
b) CH₃CHO
c) C₆H₅CHO
d) CH₃COCH₃

4. Acetone reacts with HCN to form:
a) Cyanohydrin
b) Alcohol
c) Ketal
d) Ether

5. Which test is used to distinguish aldehyde from ketone?
a) Tollen’s test
b) Iodoform test
c) Baeyer’s test
d) Benedict’s test

6. The functional group –CHO is present in:
a) Ketones
b) Aldehydes
c) Carboxylic acids
d) Esters

7. The general formula of carboxylic acid is:
a) CnH₂nO
b) CnH₂nO₂
c) CnH₂n+1O₂
d) CnH₂n−1O₂

8. Which one of the following acids is strongest?
a) Acetic acid
b) Formic acid
c) Benzoic acid
d) Propanoic acid

9. The reduction of aldehydes and ketones with NaBH₄ gives:
a) Alcohols
b) Acids
c) Esters
d) Ethers

10. Acetophenone gives positive iodoform test because it contains:
a) –CHO group
b) –COOH group
c) CH₃CO– group
d) –OH group

11. The product formed when acetaldehyde is oxidized with acidified K₂Cr₂O₇ is:
a) Acetic acid
b) Methanol
c) Ethanol
d) Ethanoic anhydride

12. Which of the following does not give iodoform test?
a) Ethanol
b) Acetaldehyde
c) Methanol
d) Acetone

13. Which reaction converts aldehyde into primary alcohol?
a) Oxidation
b) Reduction
c) Decarboxylation
d) Hydrolysis

14. Acetone on ozonolysis gives:
a) Methanol + Formic acid
b) Acetic acid + Formic acid
c) Acetic acid only
d) Formaldehyde only

15. The carboxylic acid having maximum boiling point is:
a) Formic acid
b) Acetic acid
c) Propanoic acid
d) Butanoic acid

16. Benzaldehyde does not respond to:
a) Tollen’s test
b) Fehling’s test
c) Oxidation test
d) Cannizzaro reaction

17. Which one gives effervescence with NaHCO₃ solution?
a) CH₃OH
b) CH₃CHO
c) CH₃COOH
d) C₂H₆

18. In the Rosenmund reduction, acid chlorides are reduced to:
a) Alcohols
b) Aldehydes
c) Alkanes
d) Ketones

19. Which acid is present in vinegar?
a) Formic acid
b) Acetic acid
c) Oxalic acid
d) Citric acid

20. Hell–Volhard–Zelinsky reaction is shown by:
a) Aldehydes
b) Ketones
c) Carboxylic acids
d) Esters

✅ Answer Key

  1. a
  2. d
  3. a
  4. a
  5. a
  6. b
  7. b
  8. b
  9. a
  10. c
  11. a
  12. c
  13. b
  14. b
  15. a (highest due to lowest molar mass & strongest H-bonding)
  16. b
  17. c
  18. b
  19. b
  20. c

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