58.Which of the following produces a significant amount of acetylide ion on reaction with acetylene?
(A)Conjugate base of CH₃OH (pK_a16)
(B)Conjugate base of H₂ (pK_a35)
(C)Conjugate base of H₂O (pK_a16)
(D)Both {A} and {C}
(E)Both {A} and {B}

54.Which of the following phrases are not correctly associated with SN1 reactions? 1.Rearrangements possible 2.Rate affected by solvent polarity 3.Strength of nucleophile important in determining rate 4.Reactivity series tertiary > secondary > primary 5.Proceed with complete inversion of configuration (A)3,5 (B)1,5 (C)2,3,5 (D)3 only (E)4,5

55.Which of the following statements is true concerning pKa? (A)The larger the pKa value, the weaker the acid. (B)Strong acids have small pKa values. (C)pKa = -log Ka (D)All the statements are correct. (E)All the statements are incorrect.

56.Referring to the following equilibrium (R=alkyl group)(A)K < 1 ; the equilibrium would lie the left. (B)K > 1 ; the equilibrium would lie the right. (C)K = 1 ; equal amounts of all species would be present. (D)Not enough information is given; the structure of R must be known. (E)None of these

57.Which alkyne yields butanoic acid (CH3CH2CH2CO2H) as the only organic product upon treatment with ozone followed by hydrolysis? (A)1-Butyne (B)4-Octyne (C)1-Pentyne (D)2-Hexyne (E)None of these ..

59.Hydrogenation of cyclohexene releases 120kJ/mol of heat. Which of the following most likely represents the observed heat of hydrogenation of 1,3-cyclohexadiene? (A)232kJ/mol (B)239kJ/mol (C)247kJ/mol (D)120kJ/mol (E)142kJ/mol

60.Arrange the following intermediates in order of decreasing basicity (strongest→weakest): (A)B > A > D > (B)D > A > B > C (C)C > D > A > B (D)C > B > D >A (E)D > C >B >A

61.Give the major product of the following reaction: [E]-2-pentence+ CH2I2/Zn(Cu)→ ? (A)cis-1-Ethyl-2-methylcyclopropane (B)trans-1-Ethyl-2-methylcyclopropane (C)1-Ethyl-1-methylcyclopropane (D)An equimolar mixture of product {A} and {B}(E)None of these

62.Which of the following would yield a secondary alcohol after the indicated reaction, followed by aqueous hydrolysis if necessary? (A)LiAlH4 + a ketone (B)CH3CH2MgBr + an aldehyde (C)2-Butene + mercury(II)acetate, then NaBH4, HO (D)All of these (E)None of these

63.Which of the esters shown, after reduction with LiAlH4 and aqueous workup, will yield two molecules of only a single alcohol? (A)CH3CH2CO2CH2CH3 (B)C6H5CO2C6H5 (C)C6H5CO2CH2C6H5 (D)None of these (E)All of these

64.For the following reaction, select the statement which best describes the situaton.  RCH2OH + (C5H5N)2CrO3→ (A)The alcohol is oxidized to an acid, and the Cr (VI) is reduced. (B)The alcohol is oxidized to an aldehyde, and the Cr (VI) is reduced. (C)The alcohol is reduced to an aldehyde, and the Cr (III) is oxidized (D)The alcohol is oxidized to a ketone, and the Cr (VI) is reduced. (E)The alcohol is oxidized to an acid, and the Cr (III) is reduced.