MCQ on Organic Chemistry

Test- ORGANIC Chemistry Questions: 1. Which among the following compounds will give maximum enol content in solution: 2. Which among the following compounds will show tautmerism: 3. Consider the following statement: 1. Chain and position isomerism is not possible together between two isomers. 2. Tautomerism is a chemical phenomenon which is catalysed by acid as well as base. 3. Tautomers are always metamers. 4. Tautomers are always functional isomers. Select the correct answer using the codes given below: Codes: (a) only 3 is correct (b) 3 and 4 are correct (c) 1, 2 and 4 are correct (d) 1, 2 and 3 are correct 4. Which among the following compounds will show geometrical isomerism: 5. In which compound cis-trans nomenclature cannot be used? 6. Which among the following will show geometrical isomerism: 7. Syn anti nomenclature is used in: (a) Structural isomerism (b) Optical isomerism (c) Geometrical isomerism (d) Conformal isomerism 8. Which compound will show optical isomerism: (a) 2-Butanol (b) 2-Amino butane (c) Lactic acid (d) All of these 9. Which among the following compound will have meso form: 10. Which among the following compound will be dissymmetric but not asymmetric: 11. Which among the following pairs are diastereomers: Select the correct answer from the codes given below: Codes: (a) only 2 (b) only 1 (c) 1 and 2 (d) 1, 2 and 4 12. Consider the following statements: 1. Meso form is optically inactive due to absence of diss ymmetry in the molecule. 2. Compound will be optically active if it is a dissymmetric molecule. 3. Geometrical isomers are stereoisomers. 4. Physical properties of stereoisomers are different. Select the correct answer from the codes given below: (a) Only 4 is correct (b) 1, 2 and 3 are correct (c) 1, 2 and 4 are correct (d) 2, 3 and 4 are correct 13. Which statement are correct for enantiomers: (a) Both are non-superimposable mirror image (b) Both are superimposable nirror images (c) Physical properties are different (d) Reaction velocity with optically active compound is the same. 14. Number of configurational isomers of 2, 3-dibromocinnamic acid is: (a) 4 (b) 3 (c) 2 (d) 1 15. How many geometrical isomers are possible for given compound : (a) 3 (b) 4 (c) 2 (d) 1 16. Number of configurational isomers of ethane is: (a) Two (b) Four (c) Infinite (d) Six 17. Consider following compounds: Consider the following statements: 1. (i) and (ii) are enantiomers 2. (iii) is meso form 3. (i) and (iii) are disstereomers 4. (i) and (ii) are diastereomers. Select the correct statements from the codes given below: (a) Only 2 (b) 1, 2 and 3 (c) 1, 2, 3 and 4 (d) 2, 3 and 4 18. First member of optically active alkine is: 19. Which alkine will give meso form with Br2 20. Which alkine will give meso form with Baeyer’s reagent: 21. Which alkine will form (dl) mixture with Br2: 22. In which compound cis-trans nomenclature cannot be used: 23. Which configuration is erythro: 24. Which among the following compound has (L) configuration: 25. Consider the following pairs of compounds: Which among the following statements is correct: 1. Both are enantiomers 2. Both are in threo form 3. Both are diastreomers 4. Both are in enythro form (a) 1 and 2 (b) 1, 2 and 3 (c) 2 and 3 (d) 3 and 4 26. The process of separation of racemic mixture into (+) and (-) enantiomers is called: (a) Rearmisation (b) Resolution (c) Revolution (d) Walden inversion 27. The conversion of enantiomer into racemic mixture is known as: (a) Resolution (b) Racemisation (c) Revolution (d) Inversion 28. Meso tartaric acid is optically inactive ue ti the presence of: (a) Two chiral carbons (b) Molecular asymmetry (c) Molecular symmetry (d) External compensation 29. (+) Lactic acid and (-) lactic acid are: (a) Enantiomers (b) Diastreomers (c) Tautomers (d) Structural isomers 30. According to Baeyer’s strain theory which cycloalkane is the most stable: (a) Cyclopropane (b) Cyclopentane (c) Cyclohexane (d) Cyclobutane 31. Two isomers A and B can be separated from their mixture if energy barrier will be: (a) 0.6 Kcal / mole (b) 9 Kcal / mole (c) 16 Kcal / mole (d) 12 Kcal / mole 32. Conformational isomers are due to: (a) Free rotation about C, C single bond (b) Frozen rotation about C, C single bond (c) Frozen rotation about C, C double bound (d) Restricted rotation about C, C single bond 33. Energy barrier between staggered and eclipsed ethane is: (a) 0.6 Kcal / mole (b) 2.9 Kcal / mole (c) 12 Kcal / mole (d) 16 Kcal / mole 34. The energy barrier between chain and boat form of cyclohexane is: (a) 6 Kcal / mole (b) 11 Kcal / mole (c) 0.6 Kcal / mole (d) 16 Kcal / mole 35. Bond angle in cyclohexane is: (a) 109.5o (b) 120o (c) 111o (d) 60o 36. Chair from of cyclohexane is more stable than boat form because: (a) In chair from all the six carbons are in staggered from and in boat from two carbons are in eclipsed form: (b) In chair form all the six carbons are in staggered form and in boat form all the carbons are in eclipsed form. (c) Bond angle in chair form is 111o and bond angle in boat form is 109.5o (d) Bond angle in chair form is 109.5o and in boat form 111o. 37. Which conformation of n-butane is most stable? (a) Anti staggered (b) Fully eclipsed (c) Eclipsed (d) Guaxhe staggered 38. Angle strain in which compound is maximum: (a) Propane (b) Cyclopropane (c) n-butane (d) Cyclobutane 39. Flagpole interaction is present in: (a) Boat form of cyclohexane (b) Chair form of cyclohexane (c) Anti form of n-butane (d) Fully eclipsed form of n-butane 40. Three membered cyclic compound are highly reactive because of: (a) High degree of torsional strain (b) High degree of angle strain (c) High degree of streic strain (d) All of these Geometry in the given compound is: 41. (a) cis (b) trans (c) cis aswell as trans (d) No geometrical isomerism 42. The given reaction Is an example of: (a) Stereospecific reaction (b) Stereoslective reaction (c) Both (d) Ordinary reaction 43. Optical activity is measured by: (a) Polarimeter (b) Refracto (c) Spectrograph (d) Tracer technique 44. In the reaction sequence Product will be (a) cis alkine (b) trans alkine (c) Mixture of cis and trans alkine (d) Mixture of diastreomers 45. Which one of the following alkine, when reacted with HBr produceds racemic mixture? (a) 2, 3-Dimethyl-2-butane (b) 2-Methylpropane (c) 1-Butane (d) Propane 46. In which compound hydrogen bonding is possible: (a) Ethyl alcohol (b) m-nitrophenol (c) o- nitrophenol (d) All of these 47. Which compound has maximum bp? (a) Benzene (b) Ethylene (c) Propanaldehyde (d) Acetone 48. Carotenes are soluble in: (a) Petrol (b) K-oil (c) Benzene (d) All of these 49. Which among the following compound will form intramolectular hydrogen bond: (a) Acetone (b) Nitroethane (c) 1, 3-pentanedione (d) Benzaldehyde 50. Which compound maximum mp: (a) 1-Butane (b) Butane (c) cis-2-butane (d) trans-2-butane Answers: 1 d 2 d 3 c 4 d 5 c 6 d 7 c 8 d 9 c 10 c 11 c 12 b 13 a 14 c 15 b 16 c 17 a 18 b 19 b 20 a 21 a 22 d 23 a 24 c 25 a 26 b 27 b 28 c 29 a 30 b 31 a 32 d 33 b 34 b 35 c 36 a 37 a 38 b 39 a 40 b 41 b 42 c 43 a 44 a 45 c 46 d 47 d 48 d 49 c 50 d 1 *** Mrs. Shallu Aggarwal Mobile #. 98786-08983 ***