67.Heating a particular ether with HBr yielded a single organic product. Which of the following conclusions may be reached?
(A)The reactant was a methyl ether.
(B)The reactant was a symmetrical ether.
(C)The reactant was a cyclic ether.
(D)Both {B}and {C} are correct
(E) Both {A} and {B} are correct

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.

65.Which of the following alcohols gives the best yield of diakyl ether on being heated with a trace of sulfuric acid? (A)1-Pentanol (B)2-Pentanol (C)Cyclopentanol (D)2-Methyl-2-butanol (E)2-Ethyl-propanol

66.The most effective pair of reagents for the preparation of tert-butyl ethyl ether is: (A)Potassium tert-butoxide and ethyl bromide (B)Potassium tert-butoxide and ethanol (C)Sodium ethoxide and tert-butyl bromide (D)tert-Butyl alcohol and ethyl bromide (E)None of these

68.In the 1H NMR spectrum of CH3CH2CH=CH2, how many signals are expected? (A)3 (B)4 (C)5 (D)6 (E)7

69.Ionization energies are (A)always negative (B)always positive (C)usually positive but sometimes negative (D)usually negative but sometimes positive (E)usually zero

70.Rank the following in order of increasing size:Cl, Cl+ , Cl- (A)Cl < Cl+ < Cl- (B)Cl < Cl - < Cl+ (C)Cl- < Cl < Cl+ (D)Cl+ < Cl- < Cl (E)Cl+ < Cl < Cl-

71.When carbon bonds to chlorine, the bond will be ___ and ___ atom bears a partial negative charge. (A)nonpolar, neither (B)polar, the carbon (C)polar, the chlorine (D)nonpolar, the carbon (E)nonpolar, the chlorine

72.Which of the following is (or are) the rate law for a reaction that is first order in oxygen? (A)rate = k[NO2] (B)rate = k[NO2][O2] (C)rate = k[NO2] 2 / [O2] (D)rate = k[NO2] 2 / ([O2[N2]]) (E)All of the above

73.When a catalyst is added to a reaction system, (A)the equilibrium position is changed (B)the enthalpyis changed (C)the rate is changed (D)all of the above (E)none of the above