General Organic Chemistry PYQs Set 1 (PDF)

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Mere Teacher · Previous Year Questions JEE Main Chemistry · General Organic Chemistry · Set 1 (Q1-30)
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1. $The compound that will react most readily with NaOH to form methanol is$ (1) $(C H_{3})_{4} N^{+} I^{-}$ (2) $C H_{3} O C H_{3}$ (3) $(C H_{3})_{3} S^{+} I^{-}$ (4) $(C H_{3})_{3} C-Cl$ 2. $Which of the following compounds is not chiral ?$ (1) $1-Chloropentane$ (2) $2-Chloropentane$ (3) $1-Chloro-2-methylpentane$ (4) $3-Chloro-2-methylpentane$ 3. $Which among the following purification methods is based on the principle of "Solubility" in two different solvents?$ (1) $Column Chromatography$ (2) $Sublimation$ (3) $Distillation$ (4) $Differential Extraction$ 4. $The correct pair(s) of the ambident nucleophiles is (are): (A) AgCN / KCN (B) RCOOAg / RCOOK (C) AgNO_{2} / KNO_{2} (D) AgI / KI$ (1) $(B) and (C .) only$ (2) $(A) only$ (3) $(A) and (C) only$ (4) $(B) only$ 5. $The correct decreasing order of priority for the functional groups of organic compounds in the IUPAC system of nomenclature is:$ (1) $- COOH > - SO_{3} H > - CONH_{2} > - CHO$ (2) $- CHO > - COOH > - SO_{3} H > - CONH_{2}$ (3) $- SO_{3} H > - COOH > - CONH_{2} > - CHO$ (4) $- CONH_{2} > - CHO > - SO_{3} H > - COOH$ 6. $From the following, the least stable structure is:$ (1) (2) (3) (4) 7. $Phenyl magnesium bromide reacts with methanol to give -$ (1) $a mixture of anisole and Mg(OH)Br$ (2) $a mixture of benzene and Mg(OMe)Br$ (3) $a mixture of toluene and Mg(OMe)Br$ (4) $a mixture of phenol and Mg(Me)Br$ 8. $Given below are two statements: Statement I: Hyperconjugation is not a permanent effect. Statement II: In general, greater the number of alkyl groups attached to a positively charged C atom, greater is the hyperconjugation interaction and stabilization of the cation. In the light of the above statements, choose the correct answer from the options given below$ (1) $Statement I is false but Statement II is true$ (2) $Statement I is true but Statement II is false$ (3) $Both Statement I and Statement II are false$ (4) $Both Statement I and Statement II are true$ 9. $Which of the following is used in the estimation of carbon monoxide?$ (1) $I_{2} O_{4}$ (2) $BrO_{3}$ (3) $Cl_{2} O_{7}$ (4) $I_{2} O_{5}$ 10. $Which of the following has the shortest C - Cl bond?$ (1) $Cl - CH = CH - N O_{2}$ (2) $Cl - CH = CH - C H_{3}$ (3) $Cl - CH = C H_{2}$ (4) $Cl - CH = CH - OC H_{3}$ 11. $The order of decreasing reactivity towards an electrophilic reagent, for the following would be (i) benzene (ii) toluene (iii) chlorobenzene (iv) phenol$ (1) $(ii) >_{(} i v_{)} >_{(} i_{)} >_{(} ii i_{)}$ (2) $(iv) >_{(} ii i_{)} >_{(} i i_{)} >_{(} i_{)}$ (3) $(iv) >_{(} i i_{)} >_{(} i_{)} >_{(} ii i_{)}$ (4) $(i) > (ii) > (iii) > (i v)$ 12. $The correct order of basic strength of CH3NH2(I), (CH3)2NH(II), (CH3)3N(III), C6H5CH2NH2(IV) in gaseous phase is -$ (1) $IV < III < II < I$ (2) $IV < III < I < II$ (3) $I < II < III < IV$ (4) $IV < I < II < III$ 13. $An organic compound is estimated through Dumas method and was found to evolve 6 moles of CO_{2}, 4 moles of H_{2} O and 1 mole of nitrogen gas. The formula of the compound is:$ (1) $C_{12} H_{8} N$ (2) $C_{12} H_{8} N_{2}$ (3) $C_{6} H_{8} N_{2}$ (4) $C_{6} H_{8} N$ 14. $In Dumas method one gram of carbon compound gives 50 mL of N_{2} at 300 K and 740 mmHg pressure. If the aqueous tension at 300 K is 15 mmHg, what is the percentage of nitrogen in it?$ (1) $5.42$ (2) $10.84$ (3) $21.68$ (4) $2.71$ 15. $CORRECT order of stability for the following is CH_{2} = CH^{-}, CH_{3} - CH_{2}^{-}, CH \equiv C^{-}$ (1) $CH_{2} = CH^{-} > CH \equiv C^{-} > CH_{3} - CH_{2}^{-}$ (2) $CH \equiv C^{-} > CH_{2} = CH^{-} > CH_{3} - CH_{2}^{-}$ (3) $CH \equiv C^{-} > CH_{3} - CH_{2}^{-} > CH_{2} = CH^{-}$ (4) $CH_{3} - CH_{2}^{-} > CH_{2} = CH^{-} > CH \equiv C^{-}$ 16. $Using Kjeldahl's method over 1 g of a soil sample, the ammonia evolved could neutralise 25 mL of 1 MH_{2} SO_{4} . Then, the percentage of nitrogen present in the sample is$ (1) $100 %$ (2) $60 %$ (3) $70 %$ (4) $25 %$ 17. $The adsorbent used in adsorption chromatography is/are - A. silica gel B. alumina C. quick lime D. magnesia Choose the most appropriate answer from the options given below :$ (1) $A only$ (2) $B only$ (3) $C and D only$ (4) $A and B only$ 18. $CH_{3} - CH = CH - CH_{2} OH \to PCC CH_{3} - CH = CH - CHO Hybridisation change involved at C - 1 in the above reaction is$ (1) $s p^{3} to sp$ (2) $s p^{2} to s p^{3}$ (3) $s p^{3} to s p^{2}$ (4) $sp to s p^{2}$ 19. $Which of the following is not explained by hyperconjugation?$ (1) $Stability order of carbanions$ (2) $Stability order of free radicals$ (3) $Stability order of carbocations$ (4) $Stability of alkenes$ 20. $Which of the following is the most stable carbocation (carbonium ion)?$ (1) $C H_{3} C \oplus H_{2}$ (2) $(C H_{3})_{2} C \oplus H$ (3) $(C H_{3})_{3} C^{\oplus}$ (4) $C_{6} H_{5} C \oplus H_{2}$ 21. $Using column chromatography, mixture of two compounds 'A' and 'B' was separated. 'A' eluted first, this indicates 'B' has$ (1) $low Rf, stronger adsorption$ (2) $high Rf, weaker adsorption$ (3) $high Rf, stronger adsorption$ (4) $low Rf, weaker adsorption$ 22. $Which one of the following set of elements can be detected using sodium fusion extract?$ (1) $Sulfur, Nitrogen, Phosphorous, Halogens$ (2) $Phosphorous, Oxygen, Nitrogen, Halogens$ (3) $Nitrogen, Phosphorous, Carbon, Sulfur$ (4) $Halogens, Nitrogen, Oxygen, Sulfur$ 23. $The correct order for acid strength of compounds CH \equiv CH, CH_{2} - C \equiv CH and CH_{2} = CH_{2}$ (1) $CH \equiv CH > CH_{2} = CH_{2} > CH_{3} - C \equiv CH$ (2) $CH_{3} - C \equiv CH > CH \equiv CH > CH_{2} = CH_{2}$ (3) $CH_{3} - C \equiv CH > CH_{2} = CH_{2} > HC \equiv CH$ (4) $HC \equiv CH > CH_{3} - C \equiv CH > CH_{2} = CH_{2}$ 24. $The correct order of the basic strength of methyl substituted amines in aqueous solution is :$ (1) $C H_{3} N H_{2} > (C H_{2})_{2} NH > (C H_{3})_{3} N$ (2) $(C H_{3})_{2} NH > C H_{3} N H_{2} > (C H_{3})_{3} N$ (3) $(C H_{3})_{3} N > C H_{3} N H_{2} > (C H_{3})_{2} NH$ (4) $(C H_{3})_{3} N > (C H_{3})_{2} NH > C H_{3} N H_{2}$ 25. $The fragrance of flowers is due to the presence of some steam volatile organic compounds called essential oils. These are generally insoluble in water at room temperature but are miscible with water vapour in vapour phase. A suitable method for the extraction of these oils from the flowers is_________$ (1) $crystallisation$ (2) $distillation under reduced pressure$ (3) $distillation$ (4) $steam distillation$ 26. $Which of the following nitrogen containing compound does not give Lassaigne's test?$ (1) $Urea$ (2) $Phenyl hydrazine$ (3) $Glycene$ (4) $Hydrazine$ 27. $In Carius method of estimation of halogen, 0.25 g of an organic compound gave 0.15 g of silver bromide (AgBr) . The percentage of Bromine in the organic compound is \dots \dots \times 10^{- 1 %} (Nearest integer). (Given: Molar mass of Ag is 108 and Br is 80 g mol^{- 1})$ 28. $Following Kjeldahl's method, 1 g of organic compound released ammonia, that neutralised 10 mL of 2 MH_{2} SO_{4} . The percentage of nitrogen in the compound is______% .$ 29. $In the estimation of bromine, 0.5 g of an organic compound gave 0.40 g of silver bromide. The percentage of bromine in the given compound is _________% (nearest integer) (Relative atomic masses of Ag and Br are 108u and 80u, respectively).$ 30. $On a thin layer chromatographic plate, an organic compound moved by 3.5 cm, while the solvent moved by 5 cm . The retardation factor of the organic compound is______\times 10^{- 1}$