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.
Last updated
679 questions · page 11 of 34
- A. Antiseptic
- B. Disinfectant
- C. Germicide
- D. AlI of these options are correct
Explanation: A. Antiseptic: Formalin can act as an antiseptic, used to prevent infection in wounds or applied to tissues during surgical procedures. B.
Correct answer: AlI of these options are correct- A. Amine
- B. Imine
- C. Nitrile
- D. Hydrazones
Explanation: OPTION A: Aldehydes react with ammonia to form a primary amine through Hartmann's nitration or Hofmann rearrangement.OPTION B: The…
Correct answer: Hydrazones- A. Carboxylic acid
- B. Alpha hydroxy acid
- C. Starting material from which it is formed
- D. Alpha beta unsaturated compound
Explanation: When a carbonyl compound is treated with sodium bisulphite, a bisulfite addition product is formed.
Correct answer: Starting material from which it is formed- A. Electrophilicity
- B. Nucleophilicity
- C. Basicity
- D. Acidity
Explanation: In acid-catalyzed nucleophilic addition reactions, the carbonyl system enhances the electrophilicity of the carbonyl carbon.
Correct answer: Electrophilicity- A. sp2
- B. sp3
- C. sp
- D. dsp2
Explanation: Option A: The functional group in aldehydes is a -CHO group. The C atom in the -CHO group forms one pi bond with the O atom.
Correct answer: sp2- A. Aldehyde is given priority
- B. Aldehyde is parent
- C. Aldehyde group is present at the terminal
- D. None of these options are correct
Explanation: Aldehyde functional group (RCOH) is given position 1 as it is always present at the end .E.g H-CO-CH3 is acetaldehye and (HCO) functional…
Correct answer: Aldehyde group is present at the terminal- A. Acetone
- B. Propanol
- C. Ethanal
- D. Butanone
Explanation: Ethanal, also known as acetaldehyde, is an aldehyde with a pungent odor.
Correct answer: Ethanal- A. Coloring agent
- B. Dehydrating agents
- C. Decolorising agents
- D. Solubilizing agents
Explanation: Formaldehyde is sometimes used as a decolorizing agent in dyeing processes.
Correct answer: Decolorising agents- A. Weak electrophile
- B. Strong nucleophile
- C. Weak nucleophile
- D. Strong electrophile
Explanation: For all carbonyl compounds, nucleophilic addition reactions take place, and hence a strong nucleophile that can break the C=O bond and is…
Correct answer: Strong nucleophile- A. Dehydration
- B. Condensation reaction
- C. Disproportionation reaction
- D. Proportionation reaction
Explanation: In chemistry, disproportionation, sometimes called dismutation, is a redox reaction in which one compound of intermediate oxidation state…
Correct answer: Disproportionation reaction- A. Acid
- B. Base
- C. Water
- D. Both acid and base
Explanation: Nucleophilic addition reactions of carbonyl compounds can be catalyzed by bases where a strong nucleophilic reagent attacks the…
Correct answer: Both acid and base- A. Sugar
- B. Menthone
- C. Camphor
- D. Formamint
Explanation: Based on types of functional groups, monosaccharides (reducing sugars) may be classified as aldoses (having an aldehyde group) and ketosis…
Correct answer: Sugar- A. Basicity
- B. Nucleophilicity
- C. Electrophilicity
- D. Both Options B and C are correct
Explanation: A base-catalyzed nucleophilic addition will take place in the presence of a strong base, which is usually the conjugate base of a reagent…
Correct answer: Nucleophilicity- A. Sulphide ion
- B. Sulfite ion
- C. Hydride ion
- D. Sodium ion
Explanation: Option A is wrong because sulphide doesn't act as a nucleophile.Option: B Sodium bisulphite ionizes to form sulphite ions.
Correct answer: Sulfite ion- A. Condensation reaction
- B. Dehydration reaction
- C. Disproportionation reaction
- D. All of these
Explanation: Condensation reaction to give a water molecule alongside the production of aldol.
Correct answer: Condensation reaction- A. Cyanohydrin formation
- B. Bisulfite adduct formation
- C. Haloform formation
- D. None of these
Explanation: Sodium bisulfite is used to form adducts with aldehyde and with certain cyclic ketones. These adducts are α-hydroxysulfonic acids.
Correct answer: Bisulfite adduct formation- A. (Me)3CCHO
- B. HCHO
- C. CH3CHO
- D. C6H5CHO
Explanation: The Cannizzaro reaction, named after its discoverer Stanislao Cannizzaro, is a chemical reaction which involves the base-induced…
Correct answer: CH3CHO- A. Beta hydrogen
- B. Beta carbon
- C. Alpha carbon
- D. Alpha hydrogen
Explanation: Alpha hydrogens are hydrogen atoms directly attached to the carbon atoms adjacent to the carbonyl carbon.
Correct answer: Alpha hydrogen- A. Sodium bisulphite
- B. HCl
- C. Grignard reagent
- D. HCN
Explanation: The correct answer is Sodium bisulphite. Bulky ketones do not react easily with sodium bisulphite due to steric hindrance.
Correct answer: Sodium bisulphite- A. 2: Hydroxypropanoic acid
- B. 2: Methylpropanenitrile
- C. Hydroxyacetonitrile
- D. 2: Hydroxypropanenitrile
Explanation: Hydroxyacetonitriles can be formed by the condensation of cyanide and formaldehyde.
Correct answer: Hydroxyacetonitrile