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| Chemistry 12th Chapter 12 - Aldehydes and Ketones Questions Bank |
Chemistry 2nd Year Chapter 12 - Aldehydes and Ketones Solved MCQs, Important Short Questions and Long Questions Bank
MCQs
Please select the right answer.
1. A Nucleophilic regent will readily attack on:
2. Acetaldehyde is distinguished from other aldehydes by:
3. Acetone is oxidized with:
4. Acetone reacts with HCâ‚™ to form cyanohydrin, It is an example of:
5. Acidified oxidizing agent for the laboratory preparation of acetaldehyde is:
6. Addition of alcohol in carbonyl compounds gives acetal; the geometry of acetal is:
7. Air oxidation of methanol produces:
8. Aldehyde and ketone have higher boiling point than corresponding compounds of the following except:
9. Aldehyde forms acetal when they combine with alcohols in the presence of:
10. Aldehyde give precipitate with Fehling solution on:
11. Aldehydes combine with alcohol in presence of hydrogen chloride gas to form:
12. Aldol compound consists of:
13. Aldol product on heating undergoes:
14. At room temperature formaldehyde is:
15. Bisulphite adduct is:
16. C = O and C = C bonds are differentiated by:
17. C₂H₅CHO and (CH₃)₂CO can be distinguished by testing with:
18. Calcium acetate on dry heating yields:
19. Calcium formate Ca(HCOO)₂ on dry heating yields:
20. Cannizzaro’s reaction is not given by:
21. Carbonyl compounds react with hydroxyl amine (NH₂OH) to form:
22. Catalyst used for the laboratory preparation of formaldehyde is:
23. Clemmenson’s reduction of Ketones is carried out with:
24. Concentrated Sodium hydroxide and Benzaldehyde reacts to produce:
25. Cyanohydrins are formed from carbonyl compounds by ⎯⎯⎯⎯ reactions mechanism:
26. Ethanal has ⎯⎯⎯⎯ sigma bonds:
27. Fehling solution and Benedict solution tests are of:
28. For the preparation of CH₃CHO from calcium acetate we need:
29. Formaldehyde condenses with phenol in the presence of dilute base to yield:
30. Formalin is 40 percent aqueous solution of:
31. Hybridization of carbon in carbonyl group is:
32. In which of the following compounds, carbon number is decreased during the oxidation:
33. Isopropyl alcohol on oxidation forms:
34. It is an example of:
35. Ketones are always reduced to:
36. Ketones are prepared by the oxidation of:
37. Ketones on reduction produce:
38. Mild oxidizing agent among the following is:
39. On heating acetaldehyde with Ammonical silver nitrate solution, we get:
40. Paraldehyde is polymer of:
41. Paraldehyde is used as a:
42. Propyne on hydrolysis in presence of H₂SO₄ and HgSO₄ gives:
43. Reactivity of carbonyl compounds is due to:
44. Self condensation of Acetaldehyde in the presence of dilute alkali gives:
45. The carbon atom of the carbonyl group is:
46. The compound obtained by the reduction of Propionaldehyde with amalgamated Zinc and concentrated HCl is:
47. The hybridization of C-atom in carbonyl group is:
48. The IUPAC name of CH₃COCH (CH₃)₂ is:
49. The Nucleophilic addition reactions of carbonyl compounds are catalyzed by:
50. The reaction is known as:
51. Tollen’s regent is:
52. When aldehyde reacts with Tollen’s reagent:
53. When vapors of Isopropyl alcohol are passed over heated copper, the major product obtained is:
54. Which compounds will not give Iodoform test on treatment with I₂/NaOH?
55. Which is a mixed ketone:
56. Which is not true about Cannizzaro’s reaction:
57. Which is used as an antiseptic inhalant:
58. Which is used in the preparation of throat lozenges:
59. Which of the following aldehdyes is used to prepare urotropine medicine:
60. Which of the following aldehyde is most reactive:
61. Which of the following can produce ketone:
62. Which of the following compound is least reactive:
63. Which of the following compound will react with Tollen’s reagent:
64. Which of the following compounds is acetophenone:
65. Which of the following compounds will not give iodoform test on treatment with I₂/NaOH:
66. Which of the following compounds will not give Iodoform:
67. Which of the following does not give brick red ppt. with Fehling solution ?
68. Which of the following does not give cannizzaro reaction:
69. Which of the following does not react with phenyl hydrazine:
70. Which of the following groups does not show catalytic oxidation:
71. Which of the following is not a use of formaldehyde:
72. Which of the following is resistant to oxidation under normal condition:
73. Which of the following is used as ink preservative:
74. Which of the following is used in formation of hypnotic drug:
75. Which of the following organic compounds exhibits positive Fehling test as well as Iodoform test:
76. Which of the following reactants will render Tertiary butyl alcohol on reacting with methyl magnesium iodide?
77. Which of the following reactions is used for detecting the presence of carbonyl group?
78. Which of the following reagents will react with both Aldehydes and Ketones?
79. Which of the following test is not given by aldehyde:
80. Which of the following tests is shown by ketones:
81. Which of the following will undergo nucleophilic addition reaction more easily:
82. Which of the reagents will react with Ketones only:
83. Which one of the following compounds is not derivative of NH₃ ?
84. Which one of the following is the strongest reducing agent:
85. Which one of the following undergoes Cannizzaro’s reaction in the presence of dilute aqueous sodium hydroxide?
86. Wolf-KisHâ‚™er reduction is used for the reduction 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 HCâ‚™ on aldehdes andketones is a base catalyzed reaction. What happens when products are hydrolysed?
3. Addition of HCâ‚™ 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. HCâ‚™ 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. HCâ‚™
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)HCâ‚™ (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) HCâ‚™ (ii) NAHSO₃ (iii) H₂â‚™OH (iv) H₂â‚™NH₂
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) HCâ‚™ (ii) CH₃ - CH₂ - MgBr (iii) I₂/NaOH (iv) NH₂-NH⁻C₆H₅
24. How does acetaldehyde react with following reagents.
(i) C₂H₅Mgl (ii) HCâ‚™ (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 HCâ‚™ and give it's reaction mechanism?