22 Aldehydes and Ketones Quiz | Chemistry Quiz #mcq.cetjob - Multiple choice questions and Objectives
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Aldehydes and Ketones Quiz | Chemistry Quiz

Physical properties of carbonyl compounds
(1) Physical state : Methanal is a pungent smell gas. Ethanal is a volatile liquid, boiling points 294 K. Other aldehydes and ketones containing up to eleven carbon atoms are colourless liquids while higher members are solids.
(2) Smell : With the exception of lower aldehydes which have unpleasant odours, aldehydes and ketones have generally pleasant smell. As the size of the molecule increases, the odour becomes less pungent and more fragrant. In fact, many naturally occurring aldehydes and ketones have been used in blending of perfumes and flavouring agents.
(3) Solubility : Aldehydes and ketones upto four carbon atoms are miscible with water. This is due to the presence of hydrogen bonding between the polar carbonyl group and water molecules.
(4) Boiling points : The boiling points of aldehydes and ketones are higher than those of non polar compounds (hydrocarbons) or weakly polar compounds (such as ethers) of comparable molecular masses. However, their boiling points are lower than those of corresponding alcohols or carboxylic acids.

1. Aldehydes are isomeric with 
(a) Ketones (b) Ethers 
(c) Alcohols (d) Fatty acids 

2. Ethanedial has which functional group(s)
(a) One ketonic
(b) Two aldehydic
(c) One double bond
(d) Two double bond 
3. Acetone and acetaldehyde are
(a) Position isomers
(b) Functional isomers
(c) Not isomers
(d) Chain isomers


4. Which of the following types of isomerism is shown by pentanone
(a) Chain isomerism
(b) Position isomerism
(c) Functional isomerism
(d) All of these

5. Which of the following is a mixed ketone
(a) Pentanone
  (b) Acetophenone
(c) Benzophenone
(d) Butanone

6. Carbonyl compounds are usually
(a) Ethers, aldehydes, ketones and carboxylic acids
(b) Aldehydes, ketones and carboxylic acids
(c) Aldehydes and ketones
(d) Carboxylic acids

7. The oxidation of toluene to benzaldehyde by chromyl chloride is called

(a) Cannizzaro reaction
(b) Wurtz reaction
(c) Etard reaction
(d) Reimer-Tiemann reaction

SOL:    (c)                            

8. When a mixture of methane and oxygen is passed through heated molybdenum oxide, the main product formed is

(a) Methanoic acid (b) Ethanal
(c) Methanol (d) Methanal
SOL:   B

9. Benzoin is
(a) A compound containing an aldehyde and a ketonic group
(b) Alpha, Beta-unsaturated acid
(c) Alpha-hydroxy aldehyde
(d) Alpha-hydroxy ketone
SOL:   A

10. The oxidation of benzyl chloride with lead nitrate gives
(a) Benzyl alcohol
(b) Benzoic acid
(c) Benzaldehyde
(d) p-chlorobenzaldehyde
SOL:   B

11. The final product formed when acetaldehyde is reduced with sodium and alcohol is 
(a) Ethylene
(b) Ethyl alcohol
(c) Ethene
(d) All of these
SOL:    (b) 

12. The compound obtained by the reduction of propionaldehyde by amalgamated zinc and concentrated HCl is
(a) Propanol (b) Propane
(c) Propene (d) All of these
SOL:    (b) 

13. Formaldehyde when treated with KOH gives methanol and potassium formate. The reaction is known as
(a) Perkin reaction
(b) Claisen reaction
(c) Cannizzaro reaction
(d) Knoevenagel reaction

SOL:   (c)  In cannizaro’s reaction the one substance is oxidized and other is reduced.

14. Aldehydes and ketones give addition reaction with

(a) Hydrazine
(b) Phenyl hydrazine
(c) Semicarbazide
(d) Hydrogen cyanide
(e) All of these
SOL:   D

15. Acetaldehyde reacts with
(a) Electrophiles only
(b) Nucleophiles only
(c) Free radicals only
(d) Both electrophiles and nucleophiles
SOL:   B

16. The typical reactions of aldehyde is
(a) Electrophilic addition
(b) Nucleophilic substitution
(c) Nucleophilic addition
(d) Nucleophilic elimination

SOL:   (c) Nucleophilic as addition of HCN, NaHSO3 etc.

17. Which will not give acetamide on reaction with ammonia
(a) Acetic acid
(b) Acetyl chloride
(c) Acetic anhydride
(d) Methyl formate
SOL:   D

17. The addition of HCN to carbonyl compounds is an example of
(a) Nucleophilic substitution
(b) Electrophilic addition
(c) Nucleophilic addition
(d) Electrophilic substitution
SOL:   (c) Addition of HCN to carbonyl compounds is an example of nucleophilic addition

18. Bakelite is a polymer of
(a) HCHO + phenol
(b) HCHO + aldehyde (acetaldehyde)
(c) Phenol+ H2SO4
(d) HCHO +  acetone
SOL:   A

19. The reaction in which sodium cyanide is used
(a) Perkin reaction
(b) Reimer-Tiemann reaction
(c) Benzoin condensation
(d) Rosenmund reaction


20. Which one of the following reactions is a method for the conversion of a ketone into a hydrocarbon
(a) Aldol condensation
(b) Reimer-Tiemann reaction
(c) Cannizzaro reaction
(d) Wolf-Kishner reduction

21. Enol content is highest in 
(a) Acetone
(b) Acetophenone
(c) Acetic acid
(d) Acetyl acetone

SOL:    (d) The amount of enolic form is highest (76%) in acetyl acetone because keto group is a much better electron-withdrawing group.
22. Which one of the following reacts with HCN and Tollen's reagent, but is not oxidised by Fehling's solution
(a) Methanal (b) Ethanal
(c) Benzaldehyde (d) Acetone
SOL:   C

23. During reaction of benzaldehyde with alkali one of the product is
(a) Phenol
(b) Benzyl alcohol
(c) Benzene
(d) Benzophenone
SOL:   B

24. Acetaldehyde and acetone can be distinguished by
(a) Molisch test (b) Bromoform test
(c) Solubility in water (d) Tollen's test
SOL:   (d) 

25. CH2CHO react with aqueous NaOH solution to form
(a) 3-hydroxy butanal
(b) 2-hydroxy butanal
(c) 4-hydroxy butanal
(d) 3-hydroxy butanol 
SOL:    (a) This reaction is aldol condensation

26. Fehling solution react with HCHO to form precipitate of 
(a) White colour
(b) Yellow colour
(c) Red colour
(d) Blue colour
SOL:   (c)

27. What is the name of reaction when benzaldehyde changes into benzyl alcohol
(a) Friedel-Craft's reaction
(b) Kolbe's reaction 
(c) Wurtz reaction
(d) Cannizzaro reaction

SOL:   D

28. When acetaldehyde reacts with PCl5 the resulting compound is
(a) Ethyl chloride
(b) Ethylene chloride
(c) Ethylidene chloride
(d) Trichloro acetaldehyde

29. Grignard's reagent reacts with ethanal (acetaldehyde) and propanone to give
(a) Higher aldehydes with ethanal and higher ketones with propanone
(b) Primary alcohols with ethanal and secondary alcohols with propanone
(c) Ethers with ethanal and alcohols with propanone
(d) Secondary alcohols with ethanal and tertiary alcohols with propanone
SOL:   D

30. Base catalysed aldol condensation occurs with
(a) Benzaldehyde
(b) 2, 2-dimethyl propionaldehyde
(c) Acetaldehyde
(d) Formaldehyde
SOL:   D

31. Benzaldehyde reacts with ammonia to form
(a) Benzaldehyde ammonia
(b) Urotropine
(c) Hydrobenzamide
(d) Aniline

SOL:   C

32. Acetal is obtained by reacting in the presence of dry HCl and alcohol with
(a) Aldehyde (b) Ketone
(c) Ether (d) Carboxylic acid
SOL:   A

33. The reagent with which both aldehyde and acetone react easily is
(a) Fehling's reagent
(b) Grignard reagent
(c) Schiff's reagent
(d) Tollen's reagent
SOL:   B

34. Which of the following is used in the manufacture of thermosetting plastics
(a) Formaldehyde 
(b) Acetaldehyde
(b) Acetone
(d) Benzaldehyde
SOL:   A

35. Three molecules of acetone in the presence of dry HCl form
(a) Mesitylene
(b) Phorone
(c) Glyoxal
(d) Mesityl oxide
SOL:   B

36. Which one of the following is reduced with zinc and hydrochloric acid to give the corresponding hydrocarbon
(a) Acetamide
(b) Acetic acid
(c) Ethyl acetate
(d) Butan–2–one
SOL:   d) Butane 2-one will get reduced into butane when treated with Zinc and hydrochloric acid following Clemmensen reduction, whereas Zn/HCl do not reduce ester, acid, amide

37. Aldehydes and ketones can be reduced to corresponding hydrocarbons by
(a) Refluxing with water
(b) Refluxing with strong acids
(c) Refluxing with soda amalgam and water
(d) Refluxing with zinc amalgam and concentrated HCl

SOL:    (d)