Here is a list of important organic chemistry questions for CBSE Board Exam 2024.
Note: Try solving on your own 🙂 If you are finding any difficulty, i am just a DM away on Instagram ‘cgchemistrysolutions‘.
1. Write the IUPAC name of the following compound:
2. Arrange the following compounds in an increasing order of their acid strengths:
(CH3)2CHCOOH, CH3CH2CH(Br)COOH, CH3CH(Br)CH2COOH.
3. Write a chemical reaction in which the iodide ion replaces the diazonium group in a diazonium salt.
4. Name a substance that can be used as an antiseptic as well as a disinfectant.
5. Which compound in each of the following pairs will react faster in SN2 reaction with —OH? Why?
(i) CH3Br or CH3I (ii) (CH3)3CCl or CH3Cl
6. Explain as to why haloarenes are much less reactive than haloalkanes towards nucleophilic substitution reactions.
7. Complete the following chemical equation: CH3CH2CH=CH2 + HBr/peroxide
8. Account for the following observations:
(i) pKb for aniline is more than that for methylamine (or pKb of methylamine is less than that of aniline).
(ii) Methylamine solution in water reacts with ferric chloride solution to give a precipitate of ferric hydroxide.
(iii) Aniline does not undergo Friedel-Crafts reaction.
9. Write the names and structure of the monomers of the following polymers:
(i) Buna-S (ii) Neoprene (iii) Nylon-6
10. Complete the following reaction statements by giving the missing starting material, reagent or product as required:
11. Describe name reactions:
(a) Aldol Reaction and Cross Aldol Reaction
(b) Cannizzaro reaction
(c) Wurtz Reaction and Fittig reaction and Wurtz-Fittig Reaction
12. (a) How would you account for the following:
(i) Aldehydes are more reactive than ketones towards nucleophiles.
(ii) The boiling points of aldehydes and ketones are lower than of the corresponding acids.
(iii) The aldehydes and ketones undergo a number of addition reactions.
(b) Give chemical tests to distinguish between:
(i) Acetaldehyde and benzaldehyde
(ii) Propanone and propanol.
13. Write the IUPAC name of the following compound: CH3COCH2COCH3.
14. (i) Why is it that haloalkanes are more reactive than haloarenes towards nucleophiles.
(ii) Which one of the following reacts faster in an SN1 reaction and why?
Check out: Unique Guide to Organic Conversions (Cheat Sheet included)
15. (a) How will you bring about the following conversions?
(i) Ethanol to acetone (ii) Benzene to acetophenone
(iii) Benzoic acid to benzaldehyde
(b) Describe the following giving a suitable example in each case:
(i) Decarboxylation (ii) Cannizzaro’s reaction
16. (a) An organic compound contains 69.77% carbon, 11.63% hydrogen and the rest is oxygen. The molecular mass of the compound is 86. It does not reduce Tollens’ reagent but forms an addition compound with sodium hydrogen sulphite and gives positive iodoform test. On vigorous oxidation it gives ethanoic and propanoic acids. Deduce the possible structure of the organic compound.
(b) State reasons for the following:
(i) Monochloroethanoic acid has a higher pKa value than dichloroethanoic acid.
(ii) Ethanoic acid is a weaker acid than benzoic acid.
17. How would you carry out the following conversions?
(i) Ethyl magnesium chloride to propan-1-ol
(ii) Benzyl chloride to benzyl alcohol
18. Write the structures of the monomers of the following polymers:
(i) PVC
(ii) Polypropene
19. What are biodegradable and non-biodegradable detergents? Give one example of each type.
20. Define the following in relation to proteins:
(i) Primary structure
(ii) Denaturation
(iii) Peptide linkage
21. (a) State tests to distinguish between the following pairs of compounds :
(i) Propanal and propanone
(ii) Phenol and benzoic acid
(b) How will you bring about the following conversions :
(i) Propanone to propene
(ii) Benzaldehyde to benzophenone
(iii) Ethanol to 3-hydroxybutanal
22. Write the structure of 3-oxopentanal.
23. Why is an alkylamine more basic than ammonia?
24. Which ones in the following pairs of substances undergoes SN2 substitution reaction faster and why?
25. Complete the following chemical equations:
26. Explain what is meant by:
(i) a peptide linkage (ii) a glycosidic linkage
27. What is the repeating unit in the condensation polymer obtained by combining HO2CCH2CH2CO2H (succinic acid) and H2NCH2CH2NH2 (ethylene diamine).
28. Explain the mechanism of the following reactions:
(i) Addition of Grignard’s reagent to the carbonyl group of a compound forming an adduct followed by hydrolysis.
(ii) Acid catalysed dehydration of an alcohol forming an alkene.
(iii) Acid catalysed hydration of an alkene forming an alcohol.
29. Giving an example for each, describe the following reactions:
(i) Hofmann’s bromamide reaction
(ii) Gatterman reaction
(iii) A coupling reaction
30. (a) How are the following obtained?
(i) Benzoic acid from ethyl benzene.
(ii) Benzaldehyde from toluene.
(b) Complete each synthesis by giving the missing material, reagent or products:
31. What are the following substances? Give one example of each type.
(i) Antacid (ii) Non-ionic detergents (iii) Antiseptics
32. Write the structural formula of 1-phenylpentan-1-one.
33. Arrange the following compounds in an increasing order of basic strengths in their aqueous solutions:
NH3, CH3NH2, (CH3)2NH, (CH3)3N
34. What does ‘6, 6’ indicate in the name nylon-6,6?
35. Which one in the following pairs undergoes SN1 substitution reaction faster and why?
36. Name the four bases present in DNA. Which one of these is not present in RNA?
37. Name two fat soluble vitamins, their sources and the diseases caused due to their deficiency in diet.
38. Differentiate between molecular structures and behaviours of thermoplastic and thermosetting polymers. Give one example of each type.
39. Explain the following observations:
(i) The boiling point of ethanol is higher than that of methoxymethane.
(ii) Phenol is more acidic than ethanol.
(iii) o-and p-nitrophenols are more acidic than phenol.
40. Complete the following reaction equations:
(i) RCONH2 + LiAlH4 + H2O →
(ii) C6H5N2Cl + H3PO2 + H2O →
(iii) C6H5NH2 + Br2 (aq) →
41. Describe the following substances with one suitable example of each type:
(i) Non-ionic detergents
(ii) Food preservatives
(iii) Disinfectants
42. Write chemical equations to illustrate the following name bearing reactions:
(i) Cannizzaro’s reaction
(ii) Hell-Volhard-Zelinsky reaction
(b) Give chemical tests to distinguish between the following pairs of compounds:
(i) Propanal and Propanone
(ii) Acetophenone and Benzophenone
(iii) Phenol and Benzoic acid
43. (a) How will you bring about the following conversions:
(i) Ethanol to 3-hydroxybutanal
(ii) Benzaldehyde to Benzophenone.
(b) An organic compound A has the molecular formula C8H16O2. It gets hydrolysed with dilute sulphuric acid and gives a carboxylic acid B and an alcohol C. Oxidation of C with chromic acid also produced B. C on dehydration reaction gives but-1-ene. Write equations for the reactions involved.
44. (a) Arrange the following compounds in an increasing order of their indicated property:
(i) Benzoic acid, 4-Nitrobenzoic acid, 3,4-Dinitrobenzoic acid, 4-Methoxybenzoic acid (acid strength)
(ii) CH3CH2CH(Br)COOH, CH3CH(Br)CH2COOH, (CH3)2CHCOOH, CH3CH2CH2COOH (acid strength)
(b) How would you bring about the following conversions:
(i) Propanone to Propene
(ii) Benzoic acid to Benzaldehyde
(iii) Bromobenzene to 1-phenylethanol
45. Give the IUPAC name of the following compound:
46. Complete the equations for the following reactions:
47. How are the following conversions carried out:
(i) Aniline to nitrobenzene
(ii) Ethanamine to N-ethylethanamide
(iii) Chloroethane to propan-1-amine
48. Give one chemical test each to distinguish between the compounds in the following pairs:
(i) Methylamine and dimethylamine
(ii) Aniline and benzylamine
(iii) Ethylamine and aniline
49. Explain the following terms: (i) Invert sugar (ii) Polypeptides. Name the products of hydrolysis of sucrose. Why is sucrose not a reducing sugar?
50. What are essential and non-essential amino acids in human food? Give one example of each type.
51. (a) Illustrate the following reactions giving suitable example in each case:
(i) Ammonolysis
(ii) Coupling reaction
(iii) Acetylation of amines
(b) Describe Hinsberg method for the identification of primary, secondary and tertiary amines. Also write the chemical equations of the reactions involved.
52. (a) Write the structures of main products when benzene diazonium chloride (C6 H5 N+2 Cl– ) reacts with the
following reagents:
(i) HBF4/Heat
(ii) Cu/HBr
(b) Write the structures of A, B and C in the following reactions:
53. Which would undergo SN2 reaction faster in the following pair and why?
CH3 — CH2 — Br and CH3 — CH2 — I
54. (a) Write the structures of the main products when acetone (CH3—CO—CH3) reacts with the following
reagents:
(i) Zn—Hg/conc. HCI (ii) H2N—NHCONH2/H+
(iii) CH3MgBr and then H3O+
(b) Arrange the following in the increasing order of their boiling points:
C2H5OH, CH3—CHO, CH3—COOH
(c) Give a simple chemical test to distinguish between the following pair of compounds:
CH3CH2CHO and CH3CH2COCH3
55. (a) A compound ‘A’ of molecular formula C2H3OCl undergoes a series of reactions as shown below. Write
the structures of A, B, C and D in the following reactions:
(b) Distinguish between the following:
(i) C6H5COCH3 and C6H5CHO
(ii) Benzoic acid and methyl benzoate
(c) Write the structure of 2-methylbutanal.
56. Seeing the growing cases of diabetes and depression among young children, Mr. Lugani, the principal of one reputed school organised a seminar in which he invited parents and principals. They all resolved this issue by strictly banning junk food in school and introducing healthy snacks and drinks like soap, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Lugani conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students. After reading the above passage, answer the following questions:
(i) What are the values (at least two) displayed by Mr. Lugani?
(ii) As a student, how can you spread awareness about this issue?
(iii) What are antidepressant drugs? Give an example.
(iv) Name the sweetening agent used in the preparation of sweets for a diabetic patient.
57. Write the names and structures of the monomers of the following polymers:
(i) Buna-S (ii) Glyptal (iii) Polyvinyl chloride
58. Write the chemical equations involved when aniline is treated with the following reagents:
(i) Br2 water (ii) CHCI3 + KOH (iii) HCl
59. (i) Write the product obtained when D-glucose reacts with H2N—OH.
(ii) Amino acids show amphoteric behaviour. Why?
(iii) Why cannot vitamin C be stored in our body?
60. How do you convert the following:
(i) C6H5CONH2 (Benzamide) to C6H5NH2 (Aniline) (ii) Aniline to Phenol (iii) Ethanenitrile to Ethanamine
61. Give reasons for the following:
(i) Phenol is more acidic than ethanol.
(ii) Boiling point of ethanol is higher in comparison to methoxymethane.
(iii) (CH3)3C — O — CH3 on reaction with HI gives CH3OH and (CH3)3C — I as the main products and not (CH3)3C — OH and CH3I.
62. Write the structure of the major product in each of the following reactions:
63. Arrange the following in increasing order of their basic strength:
64. (a) Illustrate the following reactions giving suitable example in each case:
(i) Hoffmann bromamide degradation reaction
(ii) Diazotisation
(iii) Gabriel phthalimide synthesis
(b) Distinguish between the following pairs of compounds:
(i) Aniline and N-methylaniline (ii) Dimethylamine and Trimethylamine
65. (i) Which one of the following is a polysaccharide: Starch, Maltose, Fructose, Glucose
(ii) What is the difference between native protein and denatured protein?
(iii) Write the name of the vitamin responsible for the coagulation of blood.
66. Write the main products when:
(i) n-butyl chloride is treated with alcoholic KOH.
(ii) 2, 4, 6-trinitrochlorobenzene is subjected to hydrolysis.
(iii) methyl chloride is treated with AgCN.
67. Predict the products of the following reactions:
68. How do you convert the following:
(i) Prop-1-ene to 1-fluoropropane
(ii) Chlorobenzene to 2-chlorotoluene
(iii) Ethanol to propanenitrile
69. Write the structures of A, B, C, and D in the following reactions:
70. Mr. Roy, the principal of one reputed school organized a seminar in which he invited parents and principals to discuss the serious issue of diabetes and depression in students. They all resolved this issue by strictly banning junk food in schools and introducing healthy snacks and drinks like soup, lassi, milk, etc. in school canteens. They also decided to make compulsory half an hour of daily physical activities for the students in the morning assembly. After six months, Mr. Roy conducted the health survey in most of the schools and discovered a tremendous improvement in the health of the students. After reading the above passage, answer the following questions:
(i) What are the values (at least two) displayed by Mr. Roy?
(ii) As a student, how can you spread awareness about this issue?
(iii) What are tranquilizers? Give an example.
(iv) Why is the use of aspartame limited to cold foods and drinks?
71. How do you convert the following:
(i) Phenol to 2-hydroxyacetophenone
(ii) Ethyl chloride to methoxy ethane
(iii) Acetone to 2-methylpropan-2-ol
Check out: Unique Guide to Organic Conversions (Cheat Sheet included)