Hydrocarbons PYQs Set 2 (PDF)

Set 2 of 16 · Questions 31-60 of 459

In the print window choose “Save as PDF”. The file prints without a web address or date line.

Mere Teacher · Previous Year Questions JEE Main Chemistry · Hydrocarbons · Set 2 (Q31-60)
Scan or visit mereteacher.com for free PYQ practice, timed CBT tests, step-by-step solutions and BroBot AI. Answers and solutions are free with a sign-up.
31. $Which cycloalkane has the lowest heat of combustion per CH_{2} group?$ (1) $Cyclopropane$ (2) $Cyclobutane$ (3) $Cyclopentane$ (4) $Cyclohexane$ 32. $Which one of the following is an intermediate in the reaction of benzene with CH_{3} Cl in the presence of anhydrous AlCl_{3} ?$ (1) $Cl^{+}$ (2) $CH_{3}^{-}$ (3) $CH_{3}^{+}$ (4) 33. $What are X and Y in the following reaction? Pent - 2 - ene \to (i) O 3 Zn / H 2 O X + Y X Y$ (1) $CH_{3} CHO CH_{3} CH_{2} CHO$ (2) $CH_{3} CH_{2} CHO CH_{3} CH_{2} CHO$ (3) $CH_{3} CHO (CH_{3})_{2} CO$ (4) $CH_{3} CHO CH_{3} CHO$ 34. $Presence of a nitro group in a benzene ring$ (1) $activates the ring towards electrophilic substitution$ (2) $renders the ring basic$ (3) $deactivates the ring towards nucleophilic substitution.$ (4) $deactivates the ring towards electrophilic substitution.$ 35. $Which one of the following methods is neither meant for the synthesis nor for separation of amines ?$ (1) $Hinsberg method$ (2) $Hofmann method$ (3) $Wurtz reaction$ (4) $None of these$ 36. $Among the following four compounds the acidity order is : (i) Phenol (ii) Methyl phenol (iii) Meta-nitrophenol (iv) Para-nitrophenol$ (1) $(iv) > (iii) > (i) > (ii)$ (2) $(iii) > (iv) > (i) > (ii)$ (3) $(i) > (iv) > (iii) > (ii)$ (4) $(ii) > (i) > (iii) > (iv)$ 37. $Which of the following reagents will be able to distinguish between 1-butyne and 2-butyne?$ (1) $NaNH2$ (2) $HCI$ (3) $O2$ (4) $Br2$ 38. $Which of the following alkane cannot be made in good yield by Wurtz reaction?$ (1) $2,3-Dimethylbutane$ (2) $n -Heptane$ (3) $n -Butane$ (4) $n -Hexane$ 39. $Select the true statement about benzene amongst the following$ (1) $because of unsaturation benzene easily undergoes addition$ (2) $there are two types of C - C bonds in benzene molecule$ (3) $there is cyclic delocalisation of π ‐electrons in benzene$ (4) $monosubstitution of benzene gives three isomeric products.$ 40. $Which of the following molecule is not aromatic?$ (1) (2) (3) (4) 41. $Arrange benzene, n -hexane and ethyne in decreasing order of their acidic behaviour.$ (1) $Benzene > n -hexane > ethyne$ (2) $n -Hexane > benzene > ethyne$ (3) $Ethyne > n -hexane > benzene$ (4) $Ethyne > benzene > n -hexane$ 42. $The suitable reagents for the conversion of methane into methyl iodide are$ (1) $I_{2}, HNO_{2}$ (2) $I_{2}, H_{2} O_{2}$ (3) $I_{2}, H_{2} O$ (4) $I_{2}, HNO_{3}$ 43. $n-Propyl chloride reacts with sodium metal in dry ether to give$ (1) $CH_{3} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{3}$ (2) $CH_{3} - CH_{2} - CH_{3}$ (3) $CH_{3} - CH_{2} - CH_{2} - CH_{3}$ (4) $CH_{3} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{2} - CH_{3}$ 44. $Weight (g) of two moles of the organic compound, which is obtained by heating sodium ethanoate with sodium hydroxide in presence of calcium oxide is:$ (1) $18$ (2) $16$ (3) $32$ (4) $30$ 45. $Identify the correct statements with respect to cis/trans-2butene from the following I. cis-2- Butene is more polar than trans - 2 Butene II. melting point of cis- 2- Butene is greater than that of trans- 2- Butene III. boiling point of cis- 2- Butene is greater than that of trans- 2-Butene Correct answer is$ (1) $I, II only$ (2) $II, III only$ (3) $I, III only$ (4) $I, II, III$ 46. $Wurtz reaction of bromoethane gives n -butane. Sodium salt of X on heating with sodalime also results in n -butane. Compound X is$ (1) $CH_{3} CH_{2} CH_{2} COOH$ (2) $CH_{3} (CH_{2})_{3} COOH$ (3) $CH_{3} (CH_{2})_{4} COOH$ (4) $CH_{3} CH_{2} COOH$ 47. $Which of the following compounds will be most easily attacked by an electrophile?$ (1) (2) (3) (4) 48. $Which one of the following reactions gives the product with less number of carbon atoms than the starting material?$ (1) $R - X \to Na / ether$ (2) $R C O_{2} N a N a O H, C a O Δ$ (3) $RCO_{2} K \to electrolysis$ (4) $R - X + H_{2} \to Zn, HCl$ 49. $The arenium ion which is not involved in the bromination of Aniline is$ (1) (2) (3) (4) 50. $The cylindrical shape of an alkyne is due to$ (1) $two sigma C - C and one π C - C bonds$ (2) $one sigma C - C and two π C - C bonds (a) (b)$ (3) $three sigma C - C bonds$ (4) $three π C - C bonds.$ 51. $Which is the correct symbol relating the two Kekule structures of benzene?$ (1) (2) $\to$ (3) $\equiv$ (4) 52. $Replacement of Cl of chlorobenzene to give phenol requires drastic conditions, but Cl of 2,4 -dinitrochlorobenzene is readily replaced. This is because$ (1) $- NO_{2} group makes the ring electron rich at ortho and para positions$ (2) $- NO_{2} group withdraws electrons from meta position$ (3) $- NO_{2} donates electrons at meta position$ (4) $- NO_{2} withdraws electrons from ortho and para positions.$ 53. $Which of the following compounds will not undergo Friedal-Craft’s reaction easily :$ (1) $Xylene$ (2) $Nitrobenzene$ (3) $Toluene$ (4) $Cumene$ 54. $The order of decreasing reactivity towards an electrophilic reagent, for the following compounds, is (i) Benzene (ii) Toluene (iii) Chlorobenzene (iv) Phenol$ (1) $(i) > (ii) > (iii) > (iv)$ (2) $(ii) > (iv) > (i) > (iii)$ (3) $(iv) > (iii) > (ii) > (i)$ (4) $(iv) > (ii) > (i) > (iii)$ 55. $Assertion : In strongly acidic solutions, aniline becomes more reactive towards electrophilic reagents. Reason : The amino group being completely protonated in strongly acidic solution, the lone pair of electrons on the nitrogen is no longer available for resonance.$ (1) $Both Assertion and Reason are true and Reason is the correct explanation of Assertion.$ (2) $Both Assertion and Reason are true but Reason is not correct explanation of Assertion.$ (3) $Assertion is true but Reason is false.$ (4) $Assertion is false but Reason is true.$ 56. $Which of the following is Lindlar catalyst?$ (1) $Zinc chloride and HCl$ (2) $Cold dilute solution of KMnO_{4}$ (3) $Sodium and Liquid NH_{3}$ (4) $Partially deactivated palladised charcoal$ 57. $Which one of the following is the most energetic conformation of cyclohexane?$ (1) $Boat$ (2) $Twisted boat$ (3) $Chair$ (4) $Half-chair$ 58. $Which is the most suitable reagent among the following to distinguish compound (3) from rest of the compounds? (1) C H_{3} - C \equiv C - C H_{3} (2) C H_{3} - C H_{2} - C H_{2} - C H_{3} (3) C H_{3} - C H_{2} C \equiv C H (4) C H_{3} - C H = C H_{2}$ (1) $Bromine in carbon tetrachloride$ (2) $Bromine in acetic acid$ (3) $A ik . K M n O_{4}$ (4) $Ammoniacal silver nitrate$ 59. $Arrange the following in the correct order of their acidic strength H_{2} C = CH_{2} CH \equiv CH CH_{3} - C \equiv CH CH_{3} - CH_{3} I II III IV$ (1) $I < II < III < IV$ (2) $IV < I < III < II$ (3) $IV < III < II < I$ (4) $II < III < IV < I$ 60. $Liquid hydrocarbons can be converted to a mixture of gaseous hydrocarbons by$ (1) $oxidation$ (2) $cracking$ (3) $distillation under reduced pressure$ (4) $hydrolysis.$