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 28 of 34
- A. Fehling's solution test
- B. Tollens's reagent test
- C. Both A and B
- D. Baeyer's test
Explanation: Both Fehling's solution test and Tollens's reagent test are commonly used to distinguish between aldehydes and ketones.(a) Fehling's…
Correct answer: Both A and B- A. H2/Ni
- B. H2/Pt
- C. NaBH4
- D. LiAlH4
Explanation: LiAlH4, lithium aluminum hydride, is a powerful reducing agent commonly used to reduce a carboxylic group (-COOH) into alcohol (-CH2OH).
Correct answer: LiAlH4- A. Hydroxy methane
- B. Hydroxyl amin
- C. Phenyl hydrazine
- D. None of these
Explanation: Oximes are formed by the reaction of ketones or aldehydes with hydroxylamine (NH2OH) in the presence of an acid catalyst.
Correct answer: Hydroxyl amin- A. Condensation
- B. Reduction
- C. Polymerization
- D. Oxidation
Explanation: Metaformaldehyde is a polymer of formaldehyde (HCHO). It is formed by the polymerization of formaldehyde molecules.
Correct answer: Polymerization- A. Ester
- B. Alcohol
- C. Carboxylic Acid
- D. Alkane
Explanation: The Cannizzaro reaction is a disproportionation reaction of aldehydes that lack an α-hydrogen atom.
Correct answer: Alcohol- A. Aldehyde
- B. Tertiary Alcohol
- C. Alkane
- D. Carboxylic Acid
Explanation: The oxidation of primary alcohols yields aldehydes, which can be further oxidized to carboxylic acids.
Correct answer: Aldehyde- A. Ammonia
- B. Nitrogen
- C. Water
- D. H+
Explanation: The production of hydrogen cyanide (HCN) from methane involves a reaction with ammonia and oxygen in the presence of a catalyst.
Correct answer: Ammonia- A. Methanol
- B. Acetaldehyde
- C. Acetone
- D. Formaldehyde
Explanation: Formaldehyde is used in making lozenges because it acts as a preservative and helps to prevent the growth of bacteria and fungi.
Correct answer: Formaldehyde- A. Methanol
- B. Acetaldehyde
- C. Propanal
- D. Butanal
Explanation: The IUPAC name of propionaldehyde is propanal. It is a three-carbon aldehyde with the formula CH3CH2CHO.
Correct answer: Propanal- A. 5
- B. 6
- C. 7
- D. 8
Explanation: The simplest aromatic aldehyde is benzaldehyde (C6H5CHO). It has a benzene ring with a formyl group (-CHO) attached to it.
Correct answer: 6- A. Aldehydes
- B. Ketones
- C. Carbonyl group
- D. None of these
Explanation: Tollen's test is a chemical test used to distinguish between aldehydes and ketones.
Correct answer: Aldehydes- A. Methyl Alcohol
- B. Acetone
- C. Ethyl Alcohol
- D. Ethane
Explanation: This reaction is a classic example of a Grignard reaction. Ethyl magnesium bromide (CH3CH2MgBr) is a Grignard reagent, which acts as a…
Correct answer: Ethyl Alcohol- A. Primary alcohol
- B. Secondary alcohol
- C. Tertiary alcohol
- D. None of these
Explanation: The oxidation of a secondary alcohol results in the formation of a ketone.
Correct answer: Secondary alcohol- A. Haloform
- B. Cannizzaro
- C. Aldol
- D. None of these
Explanation: The haloform reaction is a specific reaction of methyl ketones (R-CO-CH3) and certain other compounds containing a CH3CO- group.
Correct answer: Haloform- A. Ethanal
- B. Methanal
- C. Ethanol
- D. Methyl alcohol
Explanation: Formaldehyde is the simplest aldehyde, with the formula HCHO. Its IUPAC name is methanal.
Correct answer: Methanal- A. Methanol
- B. Ethyl alcohol
- C. Methyl alcohol
- D. Oxidation of ethylene
Explanation: Formaldehyde is industrially prepared by the catalytic oxidation of methanol (CH3OH).
Correct answer: Methanol- A. R2C=O
- B. RCHO
- C. ROR'
- D. RCOOH
Explanation: The general formula for a ketone is R2C=O, where R represents an alkyl or aryl group.
Correct answer: R2C=O- A. Microcosm
- B. Mitigation
- C. Absorption
- D. Premonition
Explanation: The word that best fits in the blank is "absorbing."So the complete sentence is:"Some poisonous gases can enter the body by absorbing…
Correct answer: Absorption- A. is
- B. are
- C. was
- D. were not
Explanation: In the sentence 'The children as well as their mother are missing after the floods,' the correct verb is 'are' because it agrees with the…
Correct answer: are- A. If only I is most appropriate
- B. If only II is most appropriate
- C. If either I or II is most appropriate
- D. If neither I nor II is most appropriate
Explanation: Simply advising professionals (Action I) is unlikely to be effective. To solve a complex socio-economic problem, it is first necessary to…
Correct answer: If only II is most appropriate