Carboxylic Acids MCQs [Organic Chemistry]

1. Carboxylic acids are generally more acidic than alcohols because:

(A) They form unstable ions

(B) They contain two oxygen atoms

(C) They have higher molecular weight

(D) Their conjugate base is resonance-stabilized

2. The general formula of monocarboxylic acids is:

(A) CₙH₂ₙO₂

(B) CₙH₂ₙ

(C) CₙH₂ₙ₊₂O

(D) CₙH₂ₙ₋₂

3. Formic acid is also known as:

(A) Ethanoic acid

(B) Methanoic acid

(C) Butanoic acid

(D) Propanoic acid

4. Which reagent converts alcohols into carboxylic acids?

(A) KMnO₄

(B) PCC

(C) SOCl₂

(D) HBr

5. Acetic acid reacts with ethanol to form:

(A) Ether

(B) Ester

(C) Polyester

(D) Amide

6. The functional group of a carboxylic acid is:

(A) –OH

(B) –COOH

(C) –CHO

(D) –COO–

7. Carboxylic acids generally show which type of hydrogen bonding?

(A) Intramolecular

(B) Ion–dipole

(C) Intermolecular dimer formation

(D) π–π stacking

8. The simplest aromatic carboxylic acid is:

(A) Phenol

(B) Phthalic acid

(C) Toluic acid

(D) Benzoic acid

9. Carboxylic acids can be reduced to primary alcohols using:

(A) LiAlH₄

(B) H₂SO₄

(C) NaOH

(D) PCC

10. Which reaction converts nitriles into carboxylic acids?

(A) Substitution

(B) Hydrolysis

(C) Reduction

(D) Dehydration

11. The pKa of most simple carboxylic acids is around:

(A) 1

(B) 7

(C) 3–5

(D) 10–12

12. Reaction of carboxylic acid with PCl₅ gives:

(A) Ester

(B) Anhydride

(C) Acid chloride

(D) Ketone

13. Oxalic acid contains:

(A) 1 carbon

(B) 2 carbons

(C) 3 carbons

(D) 4 carbons

14. The test used for identification of carboxylic acids is:

(A) Sodium bicarbonate test

(B) Tollens test

(C) Lucas test

(D) DNPH test

15. Carboxylic acids react with ammonia to form:

(A) Aldehydes

(B) Acid amides

(C) Ketones

(D) Alcohols

16. Which of the following is the strongest acid?

(A) Acetic acid

(B) Benzoic acid

(C) Propanoic acid

(D) Trichloroacetic acid

17. Acetic acid is industrially produced by:

(A) Carbonylation of methanol

(B) Wacker process

(C) Kolbe reaction

(D) Bayer process

18. Reaction of carboxylic acid with alcohol in presence of acid catalyst is called:

(A) Substitution

(B) Addition

(C) Condensation

(D) Esterification

19. Ethanoic acid has how many alpha hydrogens?

(A) 3

(B) 1

(C) 2

(D) 0

20. Benzoic acid is prepared from toluene by:

(A) Reduction

(B) Nitration

(C) Oxidation

(D) Chlorination

21. Which acid is present naturally in vinegar?

(A) Formic acid

(B) Acetic acid

(C) Lactic acid

(D) Malic acid

22. Conversion of acid chloride to carboxylic acid is carried out by:

(A) Reaction with alcohol

(B) Reaction with CH₄

(C) Reaction with NH₃

(D) Reaction with water

23. Which of the following is a dicarboxylic acid?

(A) Formic acid

(B) Propanoic acid

(C) Malonic acid

(D) Benzoic acid

24. Common name of propanoic acid is:

(A) Formic acid

(B) Acetic acid

(C) Propionic acid

(D) Butyric acid

25. Acid strength increases with:

(A) Electron-withdrawing groups

(B) Electron-donating groups

(C) Alkyl branching

(D) Aromatic ring removal

26. Which reagent forms an anhydride from carboxylic acid?

(A) Ac₂O

(B) SOCl₂

(C) PCl₅

(D) LiAlH₄

27. The reaction of sodium bicarbonate with carboxylic acid evolves:

(A) CO

(B) H₂

(C) CO₂

(D) NO

28. Formic acid differs from other carboxylic acids because it:

(A) Is a gas

(B) Has no carbonyl group

(C) Cannot form esters

(D) Can be oxidized to CO₂

29. Carboxylic acids have higher boiling points than alcohols due to:

(A) Weak van der Waals forces

(B) Coordination bonds

(C) Ionic bonding

(D) Hydrogen bonding

30. Which catalyst is commonly used in esterification?

(A) H₂O₂

(B) NaOH

(C) H₂SO₄

(D) KOH

31. Reduction of a carboxylic acid with LiAlH₄ produces:

(A) Primary alcohol

(B) Ketone

(C) Aldehyde

(D) Secondary alcohol

32. Decarboxylation removes:

(A) H₂

(B) HCl

(C) O₂

(D) CO₂

33. Which acid is known as butanoic acid?

(A) Butyric acid

(B) Caproic acid

(C) Lactic acid

(D) Valeric acid

34. Test for aromatic carboxylic acids includes:

(A) Lucas test

(B) FeCl₃ test

(C) Soda-lime decarboxylation

(D) Iodoform test

35. Which is used to convert a carboxylic acid to an ester?

(A) NH₃

(B) ROH + H⁺

(C) H₂O

(D) SOCl₂

36. Oxidation of aldehydes gives:

(A) Carboxylic acids

(B) Alcohols

(C) Esters

(D) Ethers

37. Salicylic acid contains:

(A) One –COOH group

(B) Only –OH groups

(C) Two –COOH groups

(D) One –OH and one –COOH group

38. Which reagent distinguishes between aldehydes and carboxylic acids?

(A) Fehling solution

(B) Benedict reagent

(C) Tollen reagent

(D) NaHCO₃

39. Reaction of carboxylic acid with SOCl₂ gives:

(A) Ketone

(B) Aldehyde

(C) Acid chloride

(D) Alcohol

40. Acid strength decreases in which order?

ClCH₂COOH > CH₃COOH’)”> (A) ClCH₂COOH > CH₃COOH > CF₃COOH

ClCH₂COOH > CH₃COOH’)”> (B) CF₃COOH > ClCH₂COOH > CH₃COOH

ClCH₂COOH > CH₃COOH’)”> (C) CH₃COOH > CF₃COOH > ClCH₂COOH

ClCH₂COOH > CH₃COOH’)”> (D) CF₃COOH > CH₃COOH > ClCH₂COOH

41. Lactic acid is an example of:

(A) Halogenated acid

(B) Keto acid

(C) Amino acid

(D) Hydroxy acid

42. Carboxylic acids react with bases to form:

(A) Aldehydes

(B) Salts

(C) Esters

(D) Alcohols

43. Propanoic acid’s formula is:

(A) C₃H₆O₂

(B) C₂H₄O₂

(C) C₄H₈O₂

(D) C₅H₁₀O₂

44. The acid formed when butanol is oxidized is:

(A) Propanoic acid

(B) Butanoic acid

(C) Formic acid

(D) Acetic acid

45. The reaction of an acid chloride with water is:

(A) Reduction

(B) Dehydration

(C) Condensation

(D) Hydrolysis

46. Which acid occurs naturally in citrus fruits?

(A) Oxalic acid

(B) Lactic acid

(C) Citric acid

(D) Maleic acid

47. Adipic acid contains how many carbons?

(A) 4

(B) 5

(C) 7

(D) 6

48. Formation of an ester from acid chloride uses:

(A) H₂SO₄

(B) NH₃

(C) Alcohol + base

(D) NaHCO₃

49. Carboxylic acids undergo substitution at the:

(A) Alpha carbon

(B) Beta carbon

(C) Gamma carbon

(D) Delta carbon

50. The reaction converting a carboxylic acid to an acid anhydride is:

(A) Reduction

(B) Oxidation

(C) Hydrogenation

(D) Dehydration