2nd Year Chemistry Chapter 12 Aldehydes and Ketones Notes

chemistry 12th notes chapter No 12

1. Acetone reacts with HCₙ to form cyanohydrin, It is an example of:

 
 
 
 

2. Which is used in the preparation of throat lozenges:

 
 
 
 

3. Cannizzaro’s reaction is not given by:

 
 
 
 

4. Clemmenson’s reduction of Ketones is carried out with:

 
 
 
 

5. Calcium acetate on dry heating yields:

 
 
 
 

6. Which of the following compounds is acetophenone:

 
 
 
 

7. Which of the following reactants will render Tertiary butyl alcohol on reacting with methyl magnesium iodide?

 
 
 
 

8. Self condensation of Acetaldehyde in the presence of dilute alkali gives:

 
 
 
 

9. Aldol product on heating undergoes:

 
 
 
 

10. The carbon atom of the carbonyl group is:

 
 
 
 

11. Which of the following compound is least reactive:

 
 
 
 

12. Which of the following will undergo nucleophilic addition reaction more  easily:

 
 
 
 

13. Ketones on reduction produce:

 
 
 
 

14. Which of the following aldehdyes is used to prepare urotropine medicine:

 
 
 
 

15. Hybridization of carbon in carbonyl group is:

 
 
 
 

16. For the preparation of CH₃CHO from calcium acetate we need:

 
 
 
 

17. Formalin is 40 percent aqueous solution of:

 
 
 
 

18. The Nucleophilic addition reactions of carbonyl compounds are catalyzed by:

 
 
 
 

19. Addition of alcohol in carbonyl compounds gives acetal; the geometry of acetal is:

 
 
 
 

20. Which one of the following compounds is not derivative of NH₃ ?

 
 
 
 

21. Which of the following does not react with phenyl hydrazine:

 
 
 
 

22. In which of the following compounds, carbon number is decreased during  the oxidation:

 
 
 
 

23. Which one of the following is the strongest reducing agent:

 
 
 
 

24. Which of the following can produce ketone:

 
 
 
 

25. Aldehyde give precipitate with Fehling solution on:

 
 
 
 

26. A Nucleophilic regent will readily attack on:

 
 
 
 

27. Aldehyde forms acetal when they combine with alcohols in the presence of:

 
 
 
 

28. C = O and C = C bonds are differentiated by:

 
 
 
 

29. Which is used as an antiseptic inhalant:

 
 
 
 

30. Which of the following is used as ink preservative:

 
 
 
 

31. When vapors of Isopropyl alcohol are passed over heated copper, the major product obtained is:

 
 
 
 

32. Which of the following reagents will react with both Aldehydes and Ketones?

 
 
 
 

33. Catalyst used for the laboratory preparation of formaldehyde is:

 
 
 
 

34. The compound obtained by the reduction of Propionaldehyde with amalgamated Zinc and concentrated HCl is:

 
 
 
 

35. Which is a mixed ketone:

 
 
 
 

36. Which of the following does not give cannizzaro reaction:

 
 
 
 

37. Air oxidation of methanol produces:

 
 
 
 

38. Wolf-KisHₙer reduction is used for the reduction of

 
 
 
 

39. Which of the following is not a use of formaldehyde:

 
 
 
 

40. Paraldehyde is polymer of:

 
 
 
 

41. Which is not true about Cannizzaro’s reaction:

 
 
 
 

42. Cyanohydrins are formed from carbonyl compounds by ⎯⎯⎯⎯ reactions  mechanism:

 
 
 
 

43. Which of the following compounds will not give iodoform test on treatment  with I₂/NaOH:

 
 
 
 

44. Aldehydes combine with alcohol in presence of hydrogen chloride gas to form:

 
 
 
 

45. At room temperature formaldehyde is:

 
 
 
 

46. On heating acetaldehyde with Ammonical silver nitrate solution, we get:

 
 
 
 

47. Bisulphite adduct is:

 
 
 
 

48. Which of the following tests is shown by ketones:

 
 
 
 

49. Tollen’s regent is:

 
 
 
 

50. Which one of the following undergoes Cannizzaro’s reaction in the presence of dilute aqueous sodium hydroxide?

 
 
 
 

51. When aldehyde reacts with Tollen’s reagent:

 
 
 
 

52. Ketones are prepared by the oxidation of:

 
 
 
 

53. Which of the following compounds will not give Iodoform:

 
 
 
 

54. Which of the following does not give brick red ppt. with Fehling solution ?

 
 
 
 

55. Carbonyl compounds react with hydroxyl amine (NH₂OH) to form:

 
 
 
 

56. The IUPAC name of CH₃COCH (CH₃)₂ is:

 
 
 
 

57. Which of the following reactions is used for detecting the presence of carbonyl group?

 
 
 
 

58. Ketones are always reduced to:

 
 
 
 

59. Aldehyde and ketone have higher boiling point than corresponding  compounds of the following except:

 
 
 
 

60. Reactivity of carbonyl compounds is due to:

 
 
 
 

61. Isopropyl alcohol on oxidation forms:

 
 
 
 

62. Which of the following aldehyde is most reactive:

 
 
 
 

63. Acetone is oxidized with:

 
 
 
 

64. Which of the following is used in formation of hypnotic drug:

 
 
 
 

65. C₂H₅CHO and (CH₃)₂CO can be distinguished by testing with:

 
 
 
 

66. The hybridization of C-atom in carbonyl group is:

 
 
 
 

67. Mild oxidizing agent among the following is:

 
 
 
 

68. Calcium formate Ca(HCOO)₂ on dry heating yields:

 
 
 
 

69. The reaction is known as:

 
 
 
 

70. Which of the following groups does not show catalytic oxidation:

 
 
 
 

71. Acidified oxidizing agent for the laboratory preparation of acetaldehyde is:

 
 
 
 

72. Which of the following organic compounds exhibits positive Fehling test as well as Iodoform test:

 
 
 
 

73. Propyne on hydrolysis in presence of H₂SO₄ and HgSO₄ gives:

 
 
 
 

74. Which of the following compound will react with Tollen’s reagent:

 
 
 
 

75. Paraldehyde is used as a:

 
 
 
 

76. Which compounds will not give Iodoform test on treatment with I₂/NaOH?

 
 
 
 

77. Ethanal has ⎯⎯⎯⎯ sigma bonds:

 
 
 
 

78. Acetaldehyde is distinguished from other aldehydes by:

 
 
 
 

79. Which of the reagents will react with Ketones only:

 
 
 
 

80. Concentrated Sodium hydroxide and Benzaldehyde reacts to produce:

 
 
 
 

81. Formaldehyde condenses with phenol in the presence of dilute base to yield:

 
 
 
 

82. Aldol compound consists of:

 
 
 
 

83. Which of the following is resistant to oxidation under normal condition:

 
 
 
 

84. Which of the following test is not given by aldehyde:

 
 
 
 

85. Fehling solution and Benedict solution tests are of:

 
 
 
 

86. It is an example of:

 
 
 
 

Short Questions

1. 2,4-Dinitrophenylhydrazine can be used to have a distinction between aldehydes and ketones from other organic comounds. How?
2. Addition of HCₙ on aldehdes andketones is a base catalyzed reaction. What happens when products are hydrolysed?
3. Addition of HCₙ on aldehydes and ketones is a base catalyzed reaction. Explain.
4. Benedict’s solution reacts with aldehydes to give red ppt. Justify it?
5. Convert acetaldehyde to Lactic acid.
6. Convert acetone into 2-Propanol.
7. Explain oxidation of aldehyde.
8. Fehling’s solution reacts with aldehydes to give red ppt. Justify it?
9. Fehling’s solution reacts with aldehydes to produce red ppt. justify it.
10. For aldol condensation the presence of a-hydrogen is must in aldehydes and ketones. Give reasons?
11. Give formulae of formaldehyde and acetaldehyde.
12. Give industrial preparation of formaldehyde.
13. Give reaction for the formation of acetal.
14. Give reaction for the formation of formaldehyde from methyl alcohol.
15. Give reactions to produce -Hydroxy acid (Lactic acid) from aldehyde.
16. Give the uses of acetaldehyde?
17. Give the uses of formaldehyde?
18. Give two tests for distinguishing between aldehyde and ketone.
19. HCₙ is not directly used in aldehydes and ketones. Give reasons?
20. How acetaldehdyde in the presence of a strong base gives 2-butenal?
21. How acetaldehyde is distinguished from Formaldehyde?
22. How acetaldehyde is prepared from ethl alcohol in the laboratory?
23. How acetone would be changed to propane and tertiary butyl alcohol?
24. How acetophenone can be converted into sodium salts of benzoic acid?
25. How acids and bases acting as catalysts increase the reactivity of aldegydes and ketones?
26. How a-hydroxy acids are produced from aldehydes and ketones?
27. How aldehdes occur in nature?
28. How aldehyde reacts with phenyl hydrazine. Give its mechanism?
29. How aldehydes react with alcohols to give hemiacetals and acetals?
30. How different carboxylic acids are prepared by oxidation of ketones?
31. How do you compare aldehydes and ketones?
32. How do you compare formaldehyde and acetaldehyde?
33. How does phenylhydrazine react with CH₃CHO and CH₃COCH₃?
34. How formaldehyde and acetaldehyde undergo polymerization.
35. How formalin (formaldehyde) is prepared on commercial (large) scale?
36. How formalin is prepared on the commercial scale from methyl alcohol?
“37. How Iodoform is obtained from:
i. Acetaldehyde ii. Ethyl alcohol “
“38. How Iodoform is prepared from :
a. Ethanol b. Acetaldehyde “
39. How iodoform is prepared from ethanol and acetaldhyd?
40. How Iodoform test can be used to distinguish between methyl ketones and other ketone?
41. How the reduction process of aldehydes and ketones gives alcohols?
42. Justify that Cannizzaro’s reaction is self-oxidation reduction reaction?
43. Justify that the carbonyl group of acetaldehyde is no more there is its polymer i.e.paraldehyde?
44. NH₃ reacts with aldehydes and ketones to give cyanohydrins and then hydrazones. Justify it?
45. NH₃ reacts with formaldehyde in different manner from other aldehydes and ketones. Justify it?
46. Only methyl ketones are able to give haloform reaction but other ketones do not. Give reasons?
47. Polymerization of formaldehyde gives six membered cyclic comounds. Justify it?
48. Prepare acetone from calcium acetate?
49. The addition product of an aldehyde and a ketone with NaHSO₃ is very useful reaction. Justify it?
50. The reactions of hydroxylamine hydrazine and phenyl hydrazine with aldehydes and ketones are just like the reactions of NH₃ with aldehyde and ketone. Justify it?
51. Tollen’s test is also called silver mirror test justify it?
52. Whar are those factors which make aldehdes more reactive than ketones?
53. What are aldehydes and ketones? Give examples.
54. What is difference between aldehyde and ketone?
55. What is Fehling’s solution test to identify the aldehyde?
56. What is Formalin?
57. What is silver mirror’s test? What is its importance?
58. What is Tollen’s test? Illustrate your answer with chemical equation.
59. What products are obtained when benzaldehyde reacts with 50% KOH?
60. What type of polarity is present in carbonyl group?
61. Which are those weak oxidizing agents which can oxidize aldehydes but not the ketones?
62. Which product is obtained by geating calcium acetate?
63. Why NaHSO₃ does not give the reaction with 2-pentanone?
64. Why the aldehdes with no a-hydrogen give Cannizzaro’s reaction?
65. With the haloform reaction we can decrease the number of carbon atoms in aldehydes and ketones.How?
66. Write down four uses of Acetaldehyde.
“67. Write equations for the reactions of acetaldehyde with:
i. NaHSO₃ ii. HCₙ “
68. Write the names of weak oxidizing agents which can oxides aldehydes but not ketones.
69. Write the reaction of phenyl hydrazine with acetaldehyde and acetone.

Long Questions

1. Prepare Acetaldehyde from: (i) Calcium Acetate ii) Ethyl Alcohol
2. Write laboratory and Industrial preparation for Acetaldehyde.
3. Describe the laboratory method of preparation of formaldehyde with diagram.
“4. How does formaldehyde reacts with the following reagents?
(i)HCₙ (ii) NaHSO₃
(iii) NaBH₄ / H₂O (iv) Conc. NaOH”
5. Discuss reactions of ethanol & propanone with: i) Hydroxylamine ii) Phenyl hydrazine
6. Write the reactions of ethanal with: (i) HCₙ (ii) NAHSO₃ (iii) H₂ₙOH (iv) H₂ₙNH₂
7. Write the reaction mechanism of an aldehyde with an derivative.
“8. Give reactions of acetone & acetaldehyde with:
(i) Hydroxyl amino ii) Hydrazine”
9. Explain the mechanism of reaction of phenylhydrazine with Acetone.
10. Define aldol condensation. Give its mechanism.
11. Define Cannizaro’s reaction. lain its mechanism with a suitable example.
12. Discuss reduction of compounds with sodium borohydribde with proper mechanism.
13. Why oxidation of ketones does not occur easily? What strong oxidizing agent is used to oxidize ketones.
14. Discuss Haloform reactions with one example.
15. Write the chemical equation involved in Tollens and Fehling’s solution test. Give colour of precipitates formed in each case. Why
16. Describe various tests for identification of carbonyl compounds.
17. Discuss oxidation of aldehyde with: (i) K₂Cr₂O₇/ H₂SO₄ (ii) Tollen’s reagent.
18. Write four tests by which aldehydes can be distinguished from ketones.
19. Write any four uses of acetaldehyde.
“20. Convert the following:
i) Propyne into acetone (ii) Ethyne into oxalic acid & 3-pentanone “
21. Distinguish between (i) Butanone & 3-Pentanone (ii)Acetaldehyde & benzaldehyde
22. Prepare Acetaldehyde cyanohydrine from acetaldehyde and then convert into 2-hydroxypropanoic acid.
23. Write equations for the reactions of Acetaldehyde with. (i) HCₙ (ii) CH₃ – CH₂ – MgBr (iii) I₂/NaOH (iv) NH₂-NH⁻C₆H₅
“24. How does acetaldehyde react with following reagents.
(i) C₂H₅Mgl (ii) HCₙ (iii) NaHSO₃ (iv) I₂/NaOH”
“25. By using propanone as a starting material, how would you get:
i) acetic acid ii) isoprophl alcohol”
26. Write a note on oxidation of aldehydes and ketones.
27. Write down any eight uses of Formaldehyde.
28. Describe with mechanism Aldol condensation reaction. Why Formaldehyde does not give this reaction?
29. What types of Aldehydes give Cannizzaro’s reaction? Give its mechanism.
30. Explain with Mechanism the addition of Sodium Bisulphite to Acetone. What is the utility of this reaction?
31. How does acetone react with HCₙ and give it’s reaction mechanism?

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