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 30 of 34
- A. Coloring agent
- B. Dehydrating agent
- C. Decolorizing agent
- D. solubilizing agent
Explanation: Formaldehyde is used in the synthesis of dye fixing agents in dyeing. Also used in disperse dyeing
Correct answer: Decolorizing agent- A. Benzaldehyde
- B. Acetone
- C. Benzophenone
- D. Benzyl alcohol
Explanation: OPTION A: Aldehydes that have no a -hydrogen atoms undergo Cannizzaro's reaction.
Correct answer: Benzaldehyde- A. Bakelite
- B. Paraldehyde
- C. Meta-formaldehyde
- D. All of these
Explanation: Under acidic conditions, formaldehyde polymerizes to form meta-formaldehyde, which is a cyclic structure comprising 3 formaldehyde…
Correct answer: Meta-formaldehyde- A. A
- B. B
- C. C
- D. D
Explanation: Ketone is a functional group with the structure R2C=O, where R can be a variety of carbon-containing substituent
Correct answer: B- A. More stearic hindrance offered by its methyl groups
- B. Electron withdrawing nature of its methyl groups
- C. Its carbonyl carbon is sp2 hybridized
- D. Oxygen of carbonyl group is more electronegative than carbon atom
Explanation: Acetone is less reactive towards nucleophilic addition reaction as compared to acetaldehyde due to greater I-effect of the two alkyl group…
Correct answer: More stearic hindrance offered by its methyl groups- A. Formaldehyde
- B. Acetaldehyde
- C. Dicmthyl ketone
- D. Propionoldehyde
Explanation: Aldehydes that have no ɑ-hydrogen atoms undergo cannizzaro's reaction. Acetaldehyde possess ɑ-hydrogen therefore it does not give…
Correct answer: Formaldehyde- A. They have higher boiling points than that of alkalies
- B. Theyhave lower boiling points than that of alcohols
- C. They have higher boiling point than resulting camphor.
- D. Aldehydes have H-bonding but ketones do not have
Explanation: This statement OPTION D is generally correct. Aldehydes can participate in hydrogen bonding because they have a hydrogen atom directly…
Correct answer: Aldehydes have H-bonding but ketones do not have- A. Aldehydes on reduction with NaBH4/H3O+ give 1o alcohol
- B. Ketones on reduction with NaBH4/H3O+ give 2o alcohol
- C. Aldehydes on reduction with N2H4/KOH gives alkane
- D. All of these
Explanation: Option B is correct.No, ketones on reduction with NaBH4/H3O+ do not give 2o alcohols.
Correct answer: Ketones on reduction with NaBH4/H3O+ give 2o alcohol- A. Sodium bisulphite
- B. HCI
- C. Grignard reagent
- D. HCN
Explanation: The reason why bulky ketones do not react with sodium bisulphite is because the bulky groups on the ketone make it difficult for the…
Correct answer: Sodium bisulphite- A. K2Cr2O7/H2SO4
- B. HNO3
- C. Tollen's reagent
- D. All of these
Explanation: Aldehydes can be oxidized by all of the listed oxidizing agents. Therefore, option d is correct.
Correct answer: All of these- A. Sulphide ion
- B. Sulphite ion
- C. Hydride ion
- D. Sodium ion
Explanation: In the addition of sodium bisulfite (NaHSO3) to a carbonyl system, the nucleophile is the sulfite ion (SO32-).
Correct answer: Sulphite ion- A. Electrophilic addition
- B. Electrophilic substitution
- C. Nucleophilic addition
- D. Nucleophilic substitution
Explanation: The correct answer is c) Nucleophilic addition. Acetone reacts with HCN through nucleophilic addition to form a cyanohydrin.
Correct answer: Nucleophilic addition- A. benzyl alcohol + sodium formate
- B. sodium benzoate + methanol
- C. benzyl alcohol + methanol
- D. sodium benzoate + sodium formate
Explanation: When a mixture of benzaldehyde and formaldehyde is heated with aqueous NaOH (sodium hydroxide) solution, it undergoes a reaction known as…
Correct answer: benzyl alcohol + sodium formate- A. sp3 hybridized
- B. sp hybridized
- C. sp2 hybridized
- D. un hybridized
Explanation: In aldehydes and ketones, the carbon of the carbonyl group is indeed sp2 hybridized.
Correct answer: sp2 hybridized- A. Formaldehyde
- B. Acetaldehyde
- C. Methyl ethyl ketone
- D. Acetone
Explanation: When calcium acetate undergoes dry distillation, it does indeed result in the formation of acetone.
Correct answer: Acetone- A. Butanol
- B. Propanal
- C. Propanol
- D. Butanal
Explanation: In summary, the compound with the highest boiling point among the given options is "a) Butanol." Butanol can form strong hydrogen bonds…
Correct answer: Butanol597. The question is
- A. cyanamide process
- B. Haber process
- C. Serpeck's process
- D. Contact process
Explanation: The Haber process, also called the Haber-Bosch process, is the main industrial procedure for the production of ammonia.
Correct answer: Haber process- A. CH3COOH
- B. HCOOH
- C. C2H5OH
- D. Phenol
Explanation: HCOOH, or formic acid, is the strongest acid out of the options
Correct answer: HCOOH- A. (CH3)2CO
- B. C3H7COCH2CH2CH3
- C. C2H5OC2H5
- D. C2H5CO(CH2)2CH3
Explanation: The unsymmetrical ketones have two different alkyl groups on either side of carbonyl group like
Correct answer: C2H5CO(CH2)2CH3600. Addition of HCN to acetaldehyde in the presence of dilute mineral acid and sodium cyanide forms
- A. Formaldehyde cyanohydrin
- B. Acetaldehyde cyanohydrin
- C. Acetone cyanohydrin
- D. Butanone cyanohydrin
Explanation: When HCN is added to a carbonyl compound like acetaldehyde, a nucleophilic addition reaction occurs, resulting in the formation of a…
Correct answer: Acetaldehyde cyanohydrin