Free Aldehydes and Ketones MCQs with Answers
679 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.
Aldehydes and ketones contain the polar carbonyl group, but aldehydes are generally more readily oxidised and more reactive than ketones. Coverage includes preparation by oxidation or reduction routes, nucleophilic addition of reagents such as hydrogen cyanide and bisulfite, and tests that distinguish aldehydes from ketones.
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679 questions · page 17 of 34
- A. H-СО-Н <H-CO-R < R-CO-R
- B. H-CO-R< H-CO-R ≥ R-CO-R
- C. H-CO-H > H-CO-R > R-CO-R
- D. H-CO-H> R-CO-R> H-CO-R
Explanation: Formaldehyde is the most reactive towards nucleophiles due to high electrophilicity and low steric hindrance.
Correct answer: H-CO-H > H-CO-R > R-CO-R- A. 2-Chloropentanal
- B. 2-Chloropentanol
- C. 4-Chloropentanal
- D. 4-Chloropentanol
Explanation: The correct answer is C: 4-Chloropentanal. To determine the IUPAC name, first identify the longest carbon chain that includes the aldehyde…
Correct answer: 4-Chloropentanal- A. Formaldehyde
- B. Acetaldehyde
- C. Butyraldehyde
- D. Propionaldehyde
Explanation: Formaldehyde (HCHO) is the most reactive towards nucleophilic addition among the given options.
Correct answer: Formaldehyde- A. Ethanal
- B. Methanal
- C. Butanal
- D. Proponal
Explanation: Methanal is the correct IUPAC name for formaldehyde, as it has one carbon atom and an aldehyde functional group.
Correct answer: Methanal- A. Trigonal and sp³
- B. Linear and sp²
- C. Linear and sp
- D. Planar and sp²
Explanation: Planar and sp²) - Correct: Carbonyl carbon has sp² hybridization with a planar shape.
Correct answer: Planar and sp²- A. 2,4-DNPH & sodium nitroprusside test
- B. Fehling's solution & Tollens' reagent test
- C. Benedict's solution & sodium bisulfite test
- D. 2,4-DNPH & sodium bisulfite test
Explanation: 2,4-DNPH & sodium bisulfite test) - Correct: Both react with aldehydes and ketones by forming derivatives.
Correct answer: 2,4-DNPH & sodium bisulfite test- A. Alcohols
- B. Esters
- C. Cyanides
- D. Ethers
- E. Aldehydes
Explanation: The neutral species ROH and H2O are weak nucleophiles. ROH due to the inductive effect of alkyl better nucleophile than HOHThe neutral…
Correct answer: Ethers- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: The given reaction is Friedel Craft Acylation. Given C2H5OCl in the presence of AlCl3 leads to the addition of C2H5O to the benzene ring.
Correct answer: Option B- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Alcohols add reversibly to aldehydes and ketones to form hemiacetals. This reaction can continue by adding another alcohol to form an…
Correct answer: Option D- A. Beta Hydroxy carboxylic acids
- B. Alpha hydroxy carboxylic acids
- C. Carboxylic acids
- D. Unsaturated acids
Explanation: Hydrolysis of cyanohydrin derivative produces carboxylic acids. Cyanohydrin derivatives are obtained by addition of a molecule of HCN to…
Correct answer: Alpha hydroxy carboxylic acids- A. Acetylides
- B. Paraldehyde
- C. Bakelite
- D. Meta Acetaldehyde
Explanation: In the presence of concentrated H2SO4, Acetaldehyde is polymerized to Paraldehyde. Acetaldehyde + conc. H2SO4 = paraldehyde
Correct answer: Paraldehyde- A. Dehydration
- B. Polymerization
- C. Condensation
- D. Oxidation reaction
Explanation: Acetaldehyde is polymerised to paraldehyde in the presence of concentrated H2SO4 or concertrated HCl thus, option B is correct.
Correct answer: Polymerization- A. Ketone
- B. Secondary alcohol
- C. Aldehyde
- D. Ketone and alcohol
Explanation: The addition of Grignard reagent (RMgX) to acetaldehyde will hydrolyze it to give secondary alcohol.
Correct answer: Secondary alcohol- A. H2SO4
- B. K2Cr2O7
- C. NaOH
- D. H2O/H+
Explanation: An alkaline catalyst is required for the aldol condensation reaction.
Correct answer: NaOH- A. Fehling's solution test
- B. Benedict's solution test
- C. Silver mirror test
- D. Sodium nitroprusside test
Explanation: The Benedict's solution test is also used to test for the presence of reducing sugars.
Correct answer: Benedict's solution test- A. Carboxylic acid
- B. Alpha hydroxy acid
- C. Starting material from which it is formed
- D. Alpha beta unsaturated compound
Explanation: Aldehydes and small methyl ketones react with a saturated aqueous solution of sodium bisulfate to form a Crystalline white ppt of sodium…
Correct answer: Starting material from which it is formed- A. Red precipitate
- B. Yellow precipitate
- C. Silver mirror
- D. Brick red precipitate
Explanation: Tollens' reagent oxidizes an aldehyde into the corresponding carboxylic acid.
Correct answer: Silver mirror- A. Alkanol
- B. Alkanal
- C. Alkanone
- D. Alkyl halides
Explanation: Is correct as in iupac naming the "one" suffix is used for ketone .It is a PTB line
Correct answer: Alkanone- A. One Carboxylic acid
- B. Mixture of different carboxylic acids
- C. Same type of carboxylic acids
- D. None of these
Explanation: Is Correct as in case of symmetrical ketones, only one carbon atom adjacent to the carbonyl group is oxidized and a mixture of two…
Correct answer: Mixture of different carboxylic acids- A. Propanone
- B. Pentanol
- C. Benzaldehyde
- D. Hexanol
Explanation: Benzaldehyde is an aromatic aldehyde. It contains a benzene ring with an aldehyde functional group (-CHO) attached to it.
Correct answer: Benzaldehyde