Aldehydes & Ketones MCQs set 3 for GIKI Entry Test Chemistry — 20 solved questions.
Q1. What is the product of the reaction between acetone and chloroform?
Answer: Chloretone
Explanation: The reaction between acetone and chloroform results in the formation of chloretone, a hypnotic compound.
Q2. The compound that does not react with Fehling's solution is
Answer: Benzaldehyde
Explanation: Benzaldehyde does not react with Fehling's solution as it is an aromatic aldehyde lacking alpha hydrogen.
Q3. Cannizzaro reaction is given by
Answer: Aldehydes without alpha hydrogen
Explanation: Cannizzaro reaction occurs in aldehydes without alpha hydrogen, resulting in disproportionation.
Q4. The reaction of aldehydes with hydroxylamine results in the formation of
Answer: Oximes
Explanation: Aldehydes react with hydroxylamine to form oximes, which are used for characterization.
Q5. The reaction of ketones with Grignard reagents results in the formation of
Answer: Tertiary alcohols
Explanation: Grignard reagents add to ketones, resulting in the formation of tertiary alcohols after hydrolysis.
Q6. The compound that is used as a starting material for the synthesis of many pharmaceuticals is
Answer: Benzaldehyde
Explanation: Benzaldehyde is used as a starting material for the synthesis of many pharmaceuticals due to its versatility in reactions.
Q7. The reaction of aldehydes with ammonia results in the formation of
Answer: Aldehyde ammonia
Explanation: Aldehydes react with ammonia to form aldehyde ammonia, which is used in various applications.
Q8. The compound that is not an aldehyde or ketone is
Answer: C6H5COOH
Explanation: C6H5COOH is benzoic acid, which is a carboxylic acid, not an aldehyde or ketone.
Q9. The reaction of ketones with sodium borohydride results in the formation of
Answer: Secondary alcohols
Explanation: Sodium borohydride reduces ketones to secondary alcohols.
Q10. The reaction of aldehydes with phenylhydrazine results in the formation of
Answer: Phenylhydrazones
Explanation: Aldehydes react with phenylhydrazine to form phenylhydrazones, which are used for characterization.
Q11. The compound that is used as a solvent and as a precursor to many chemicals is
Answer: Acetone
Explanation: Acetone is widely used as a solvent and as a precursor to many chemicals due to its properties.
Q12. The reaction of ketones with 2,4-dinitrophenylhydrazine results in the formation of
Answer: 2,4-Dinitrophenylhydrazones
Explanation: Ketones react with 2,4-dinitrophenylhydrazine to form 2,4-dinitrophenylhydrazones, which are used for characterization.
Q13. The compound that is responsible for the characteristic smell of almonds is
Answer: Benzaldehyde
Explanation: Benzaldehyde is responsible for the characteristic smell of almonds.
Q14. Which of the following compounds is most reactive towards nucleophilic addition?
Answer: CH₃CHO
Explanation: Aldehydes are more reactive than ketones due to less steric hindrance and more electrophilic carbonyl carbon.
Q15. The reaction of benzaldehyde with NH₂OH gives?
Answer: Oxime
Explanation: NH₂OH reacts with aldehydes to form oximes.
Q16. The reaction of aldehydes with Grignard reagent followed by hydrolysis gives?
Answer: Secondary alcohols
Explanation: Grignard reagent adds to aldehydes, forming a secondary alcohol after hydrolysis.
Q17. The compound that undergoes Cannizzaro reaction is?
Answer: C₆H₅CHO
Explanation: Aromatic aldehydes without alpha hydrogen undergo Cannizzaro reaction.
Q18. The reaction of aldehydes with ammonia gives?
Answer: Aldehyde ammonia
Explanation: Aldehydes react with ammonia to form aldehyde ammonia.
Q19. The reaction of ketones with LiAlH₄ gives?
Answer: Secondary alcohols
Explanation: LiAlH₄ reduces ketones to secondary alcohols.
Q20. The compound that is most reactive towards LiAlH₄ is?
Answer: CH₃CHO
Explanation: Aldehydes are more reactive than ketones towards LiAlH₄.