Free Reactivity of Aldehydes and Ketones MCQs with Answers
83 Reactivity of Aldehydes and Ketones MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
The polar carbonyl group makes aldehydes and ketones undergo nucleophilic addition, reduction and condensation reactions. Aldehydes are generally more reactive and oxidise readily to carboxylic acids, whereas ketones resist mild oxidation; reactions with hydrogen cyanide, sodium bisulfite and 2,4-DNP help identify their behaviour.
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83 questions · page 4 of 5
- A. Aldehyde
- B. Alcohol
- C. Both A and B
- D. Ketone
Explanation: Aldole consists of both an Aldehyde group (-CHO) and an alcohol group (-OH) in the same molecule.
Correct answer: Both A and B- A. Maleic Acid and Fumaric Acid
- B. Acetic Acid and Formic Acid
- C. Formic Acid and Oxalic Acid
- D. Oxalic Acid and Acetic Acid
Explanation: Explanation:This is an oxidation reaction. Acetone is a symmetrical ketone.
Correct answer: Acetic Acid and Formic Acid- A. Formic acid
- B. Acetone
- C. Acetaldehyde
- D. Butanone
Explanation: Explanation:Aldehydes react with tollen's reagent . So, the correct answer is C.This option is not correct because it is ethanoic acid.
Correct answer: Acetaldehyde- A. Sodium borohydride
- B. Sodium bisulphite
- C. Sodium nitroprusside
- D. Fehling's solution
Explanation: A is incorrect as sodium borohydrides converts carbonyl compounds to B is incorrect as sodium bisulphate reacts with carbonyl compounds to…
Correct answer: Fehling's solution- A. A
- B. B
- C. C
- D. D
Explanation: Iodoform test is a test for the presence of a methyl ketone or a compound containing methyl group is adjacent to the functional group.
Correct answer: A- A. 1
- B. 2
- C. 3
- D. 4
Explanation: Alpha carbon is a carbon atom bonded to a functional group in an organic compound.Carbon 2 is considered to be alpha because it has a…
Correct answer: 2- A. 2, 4-Dinitrophenyl hydrazine
- B. 1, 3-Dinitrophenyl hydrazone
- C. Phenyl hydrazone
- D. 2, 4-Dinitrophenyl hydrazone
Explanation: Hydrazone consists of a carbon-nitrogen double bond, i.e., R1R2C=NNH2. In Phenyl hydrazone, one H atom of hydrazone is replaced by a…
Correct answer: 2, 4-Dinitrophenyl hydrazine- A. 3-pentanone
- B. Propanone
- C. Propanal
- D. Butanal
Explanation: Compounds that give a positive iodoform test are primary alcohol, methyl alcohol and methyl ketones.
Correct answer: Propanone- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Ketones react with HCN in nucleophilic addition reaction and the product is a cyanohydrin i.e a compound which has OH and CN both bonded…
Correct answer: Option A- A. A red precipitate of CuO is formed
- B. A black precipitate of CuO is formed
- C. Silver mirror is formed
- D. No reaction occurs
Explanation: Aldehyde reacts with Fehling reagent through the following reaction: Diagram This is an oxidation reaction in which copper oxidizes alkyl…
Correct answer: A red precipitate of CuO is formed- A. CH3COOH
- B. C2H5OH
- C. OHC.OHC
- D. None of the above
Explanation: An aldehyde on oxidation with an oxidizing agent (such as one given in qs) gives its respective carboxylic acid. A is a carboxylic acid.
Correct answer: CH3COOH- A. Cu (I) oxide
- B. Ethanal
- C. Acetone
- D. Phenol
Explanation: Ethanal is an aldehyde and is capable of reducing Cu (ll) ions to Cu (l) ions. It will give a positive test with Fehling's solution.
Correct answer: Ethanal- A. Hoffman reagent
- B. Grignard reagent
- C. Tollens reagent
- D. Cannizaro reagent
Explanation: Tollen's reagent, which is a solution of silver nitrate in aqueous ammonia, is used to test for the presence of aldehydes and…
Correct answer: Tollens reagent- A. Talons test
- B. Fehling test
- C. Bacyer test
- D. Benedict test
Explanation: Bacyer's test is not used to identify aldehydes. Instead, it is used to detect the presence of unsaturation in organic compounds, such as…
Correct answer: Bacyer test- A. Benzaldehyde
- B. 2-Pentanone
- C. 3-Hexanone
- D. 3-Pentanone
Explanation: The iodoform test is a chemical reaction used to identify methyl ketones, which contain a CH3 group directly bonded to the carbonyl…
Correct answer: 2-Pentanone- A. Bacyer's test
- B. Fehling's test
- C. Silver mirror test
- D. Both (B) and (c)
Explanation: Both fehling's test and silver mirror test also known as tollens' test is used to distinguish between aldehydes and ketones.
Correct answer: Both (B) and (c)- A. Propanone
- B. Ethanol
- C. Butanone
- D. Methanol
Explanation: It does not have methyl group attached to alpha carbon so it will not give idoform test
Correct answer: Methanol- A. Ethanol
- B. Ethanoic acid
- C. Ethane
- D. Ethylene
Explanation: H2/Ni are strong reducing agents which reduces aldehydes to primary alcohols and ketones to secondary alcohols.
Correct answer: Ethanol- A. Acetone
- B. Ethyl acetate
- C. Formaldehyde
- D. Acetic acid
Explanation: Although both aldehydes and ketones contain the carbonyl functional group (-C=O), only aldehydes give a positive test (formation of an…
Correct answer: Formaldehyde- A. Grignard reduction
- B. Clemmenson reduction
- C. Wolf-kishner reduction
- D. Friedel-craft reduction
Explanation: The Clemmensen reduction is a reaction that is used to reduce aldehydes or ketones to alkanes using hydrochloric acid and zinc amalgam.
Correct answer: Clemmenson reduction