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 33 of 34
- A. Phenols
- B. Acetone
- C. Ethanal
- D. Methanol
Explanation: Positive iodoform test is given by a methyl ketone or a secondary alcohol with a methyl group in the alpha position.
Correct answer: Ethanal- 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. Propane
- B. Butane
- C. Methane
- D. Ethane
Explanation: Explanation:The reaction is a typical Grignard reagent hydrolysis reaction where the Grignard reagent (CH3CH2MgBr) reacts with water to…
Correct answer: Ethane- A. Nucleophilic addition
- B. Electrophilic addition
- C. Electrophilic substitution
- D. Nucleophilic substitution
Explanation: It is an example of nucleophilic addition. The CN- ion has a negative charge and it is attracted to a positive charge so CN- is a…
Correct answer: Nucleophilic addition- A. Nucleophilic addition
- B. Nucleophilic substitution
- C. Electrophilic addition
- D. Addition elimination
Explanation: This reaction is called an addition-elimination reaction since a water molecule is eliminated from the reaction whereas the lone pair of…
Correct answer: Addition elimination- A. Primary alcohols
- B. Secondary alcohols
- C. Organic acids
- D. Inorganic acids
Explanation: Consider any 1° alcohol. For simplicity consider it to be open-chain alcohol.
Correct answer: Primary alcohols- A. Acetaldehyde.
- B. Formaldehyde.
- C. None of these.
- D. Both A and B.
Explanation: Chloral is produced by chlorinating acetaldehyde or ethanol in an acidic solution by gradually increasing the temperature from 0 °C to 90…
Correct answer: Acetaldehyde.- A. Initiator
- B. Promoter
- C. Catalyst
- D. Reactant
Explanation: Explanation:In the conversion of ethylene into acetaldehyde, cupric chloride acts as promoter.
Correct answer: Promoter- A. Formaldehyde
- B. Acetaldehyde
- C. Calcium acetate
- D. Sodium acetate
Explanation: A is incorrect as formaldehyde is a product of calcium salt of formic acid.B is correct as Dry distillation of a mixture of the above…
Correct answer: Acetaldehyde- A. Ketone
- B. Aldehyde
- C. Formic Acid
- D. Ether
Explanation: Primary alcohols are oxidised to the corresponding aldehydes which are then oxidised to carboxylic acids.
Correct answer: Aldehyde- 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. CH3OH
- B. C2H5OH
- C. (CH3)2CHOH
- D. ....
Explanation: When a Grignard reagent reacts with aldehydes and ketones, it results in production of addition products which on hydrolysis gives…
Correct answer: C2H5OH- A. Alcohol and aldehyde functional groups
- B. Alcohol and ether functional groups
- C. Aldehyde and ether functional groups
- D. Alcohol and carboxylic acid functional groups
Explanation: Hemiacetal is a molecule made up of a core carbon atom connected to four groups: -OR, -OH, -R, and -H.
Correct answer: Alcohol and ether functional groups