NEET UG - Reactions including nucleophilic addition oxidation reduction aldol condensation Cannizzaro and haloform reactions Online Test (MCQ Quiz)

1. Which functional group is characteristic of aldehydes and ketones?

A) Carboxyl group (-COOH) B) Hydroxyl group (-OH) C) Carbonyl group (C=O) D) Amino group (-NH2)

2. In a nucleophilic addition reaction of a carbonyl compound, what acts as the nucleophile?

A) An electrophile B) A positively charged species C) A species with a lone pair of electrons or negative charge D) A proton (H+)

3. Which of the following reagents is commonly used for the reduction of aldehydes and ketones to primary and secondary alcohols, respectively?

A) KMnO4 B) CrO3 C) LiAlH4 D) H2SO4

4. Oxidation of a primary alcohol typically yields:

A) A secondary alcohol B) A ketone C) An aldehyde or a carboxylic acid D) An ether

5. Which reaction involves the reaction of an aldehyde or ketone with an alcohol in the presence of an acid catalyst to form an acetal?

A) Aldol condensation B) Cannizzaro reaction C) Nucleophilic addition D) Haloform reaction

6. The Aldol condensation reaction requires the presence of:

A) No alpha-hydrogens B) Alpha-hydrogens C) A strong oxidizing agent D) A strong reducing agent

7. In the Aldol condensation, what is the product formed from the reaction of two molecules of ethanal?

A) Propanal B) Butanal C) 3-Hydroxybutanal D) Butanone

8. The Cannizzaro reaction is characteristic of aldehydes that:

A) Have alpha-hydrogens B) Lack alpha-hydrogens C) Are primary alcohols D) Are secondary alcohols

9. In the Cannizzaro reaction, what are the products formed from an aldehyde lacking alpha-hydrogens in the presence of a concentrated base?

A) Two molecules of the corresponding alcohol B) One molecule of the corresponding alcohol and one molecule of the corresponding carboxylic acid salt C) Two molecules of the corresponding carboxylic acid D) One molecule of the corresponding aldehyde and one molecule of the corresponding alcohol

10. Which of the following aldehydes undergoes the Cannizzaro reaction?

A) Ethanal B) Propanal C) Benzaldehyde D) Acetaldehyde

11. The Haloform reaction is a specific test for compounds containing:

A) A methyl ketone group (CH3CO-R) or a secondary alcohol that can be oxidized to a methyl ketone B) A primary alcohol group C) An aldehyde group without alpha-hydrogens D) A carboxylic acid group

12. Which of the following reagents is used in the Haloform reaction?

A) Dilute NaOH B) Acidified KMnO4 C) A halogen (X2) and a base (like NaOH or KOH) D) LiAlH4

13. What is the characteristic precipitate formed during a positive Tollen's test for aldehydes?

A) Silver chloride (AgCl) B) Silver oxide (Ag2O) C) Silver mirror (Ag) D) Copper(I) oxide (Cu2O)

14. Tollen's reagent is an alkaline solution of:

A) Potassium permanganate B) Chromic acid C) Ammoniacal silver nitrate D) Sodium borohydride

15. Which functional group can be oxidized by Fehling's solution?

A) Ketones B) Aldehydes C) Esters D) Ethers

16. Fehling's solution A is a solution of:

A) Alkaline copper(II) sulfate B) Alkaline potassium sodium tartrate C) Acidic copper(II) sulfate D) Ammoniacal silver nitrate

17. Fehling's solution B is a solution of:

A) Alkaline copper(II) sulfate B) Alkaline potassium sodium tartrate C) Acidic copper(II) sulfate D) Ammoniacal silver nitrate

18. A positive Fehling's test results in the formation of a precipitate of:

A) Silver mirror B) Copper(I) oxide (reddish-brown) C) Copper(II) oxide (black) D) Zinc oxide (white)

19. Which type of compound is NOT oxidized by mild oxidizing agents like PCC (Pyridinium Chlorochromate)?

A) Primary alcohols B) Secondary alcohols C) Aldehydes D) Ketones

20. PCC is used to oxidize primary alcohols to:

A) Carboxylic acids B) Aldehydes C) Ketones D) Esters

21. Strong oxidizing agents like acidified KMnO4 or K2Cr2O7 can oxidize primary alcohols to:

A) Aldehydes B) Ketones C) Carboxylic acids D) Ethers

22. Secondary alcohols are oxidized to which functional group by most oxidizing agents?

A) Aldehydes B) Carboxylic acids C) Ketones D) Esters

23. Which reagent is used for the reduction of carboxylic acids to primary alcohols?

A) Na/Ethanol B) H2/Ni C) LiAlH4 D) PCC

24. The reaction of a Grignard reagent with an aldehyde followed by hydrolysis yields:

A) An aldehyde B) A carboxylic acid C) An alcohol D) A ketone

25. Cyanohydrins are formed by the nucleophilic addition of:

A) Water to aldehydes/ketones B) Hydrogen cyanide to aldehydes/ketones C) Ammonia to aldehydes/ketones D) Alcohols to aldehydes/ketones

26. Which reaction involves the self-condensation of an ester in the presence of a strong base?

A) Aldol condensation B) Claisen condensation C) Cannizzaro reaction D) Haloform reaction

27. The product of the Claisen condensation of ethyl acetate is:

A) Ethyl propanoate B) Ethyl acetoacetate C) Acetone D) Acetaldehyde

28. Which of the following is a characteristic reaction of ketones?

A) Cannizzaro reaction B) Haloform reaction (if it has a methyl ketone group) C) Oxidation to carboxylic acids with strong oxidizers D) All of the above

29. When an aldehyde reacts with hydroxylamine, what is formed?

A) An oxime B) A hydrazone C) A semicarbazone D) An acetal

30. The reaction of an aldehyde or ketone with phenylhydrazine forms a:

A) Oxime B) Hydrazone C) Semicarbazone D) Acetal

31. Which reagent is used to form semicarbazones from aldehydes and ketones?

A) Hydroxylamine B) Phenylhydrazine C) Semicarbazide D) Hydrazine

32. The Wittig reaction is used to synthesize:

A) Alcohols B) Ketones C) Alkenes D) Ethers

33. In the Wittig reaction, the nucleophile is a:

A) Carbanion from an alkyl halide B) Ylide (phosphorus ylide) C) Grignard reagent D) Organolithium reagent

34. The reaction of an aldehyde or ketone with HCN followed by acid hydrolysis yields:

A) An ester B) An alpha-hydroxy acid C) An alpha-amino acid D) An amide

35. Which of the following is NOT a nucleophilic addition reaction to a carbonyl group?

A) Reaction with HCN B) Reaction with Grignard reagent C) Reaction with alcohol to form acetal D) Oxidation by KMnO4

36. The dehydration of the aldol product (beta-hydroxy aldehyde or ketone) leads to the formation of:

A) An alpha,beta-unsaturated aldehyde or ketone B) A saturated aldehyde or ketone C) An ester D) An ether

37. Which reaction is used to distinguish between an aldehyde and a ketone?

A) Reaction with LiAlH4 B) Reaction with Tollen's reagent or Fehling's solution C) Reaction with HCN D) Reaction with an alcohol

38. When a methyl ketone (R-CO-CH3) reacts with iodine in the presence of a base, the product is:

A) A carboxylic acid salt and iodoform B) An ester and iodoform C) An aldehyde and iodoform D) An alcohol and iodoform

39. The reduction of a ketone using Wolff-Kishner reduction yields:

A) A secondary alcohol B) An alkane C) An alkene D) An ester

40. What are the conditions for Wolff-Kishner reduction?

A) Hydrazine, strong base (KOH), high temperature B) LiAlH4, dry ether C) H2, Pd/C D) Acidic conditions

41. Which type of compound can be reduced to a hydrocarbon using Clemmensen reduction?

A) Aldehyde B) Ketone C) Carboxylic acid D) Ester

42. Clemmensen reduction uses:

A) Hydrazine and KOH B) Zinc amalgam and concentrated HCl C) Lithium aluminum hydride D) Sodium and ethanol

43. Which of the following aldehydes will undergo both Cannizzaro and Aldol condensation?

A) Methanal B) Ethanal C) Propanal D) Benzaldehyde

44. The intermediate formed in the Cannizzaro reaction before disproportionation is:

A) A tetrahedral intermediate with hydride transfer B) An enolate ion C) A hemiacetal D) A cyanohydrin

45. The reaction of an alpha,beta-unsaturated carbonyl compound with a nucleophile where the nucleophile attacks the beta-carbon is called:

A) 1,2-addition B) 1,4-addition (Michael addition) C) Nucleophilic substitution D) Electrophilic addition

46. Which of the following is a characteristic of nucleophilic addition to carbonyls regarding the electron density in the carbonyl group?

A) The carbon atom is electron-rich B) The oxygen atom is electron-deficient C) The carbon atom is electron-deficient due to the electronegativity of oxygen D) The pi bond is easily broken by electrophiles

47. Oxidation of a secondary alcohol produces:

A) Aldehyde B) Carboxylic acid C) Ketone D) Ester

48. Which reaction involves the addition of a nucleophile to the carbonyl carbon followed by the elimination of a leaving group?

A) Nucleophilic addition B) Nucleophilic addition-elimination C) Electrophilic addition D) Aldol condensation

49. The reaction of a carboxylic acid derivative (like an ester or acid chloride) with a nucleophile typically involves:

A) Nucleophilic addition only B) Nucleophilic addition-elimination C) Nucleophilic substitution at the alpha-carbon D) Electrophilic attack on the carbonyl carbon

50. Which of the following is a key step in the mechanism of the Haloform reaction for methyl ketones?

A) Alpha-halogenation followed by nucleophilic attack by hydroxide B) Direct nucleophilic attack by hydroxide on the carbonyl C) Enolization followed by reaction with halogen D) Both A and C

Reactions including nucleophilic addition oxidation reduction aldol condensation Cannizzaro and haloform reactions - Online Test

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