Protic and aprotic solvents are very similar as solvents except for their ________.()
A. polarity
B. dielectric constant
C. ability to stabilize anions by hydrogen bonding
D. ability to stabilize cations by hydrogen bonding
E. ability to stabilize cations with unshared pairs of electrons
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Which of the following statements is true concerning the E2 reactions of alkyl fluorides?()
Alkyl fluorides react more readily in E2 reactions than do alkyl iodides.
B. The transition state of this E2 reaction resembles a carbanion rather than an alkene.
C. The C-F bond is the weakest carbon-halogen bond so SN2 will always predominate over E2 in the reactions of alkyl fluorides.
D. Alkyl fluorides react to form the most stable carbocation intermediate.
E. Alkyl fluorides cannot adopt the proper stereochemical alignment for an E2 reaction to occur.
Which of the following species is most reactive in an SN2 reaction?()
A. CH3CH2—Cl
B. CH3CH2—Br
CH3CH2—I
D. CH3CH2—F
E. CH3CH2—OH
Which of the following statements concerning SN2 reactions of alkyl halides is not correct?()
A. The rate of reaction depends on the concentration of the nucleophile.
B. The rate of reaction depends on the concentration of the alkyl halide.
C. The rate of reaction of a particular alkyl bromide depends on the steric accessibility of the carbon of the C-Br bond.
D. All alkyl iodides react more rapidly than all alkyl chlorides.
E. The rate of reaction depends on the relative nucleophilicity of the nucleophile.
Which of the following correctly describes the relative nucleophilicities of methoxide and tert-butoxide?()
A. These alkoxides have essentially the same nucleophilicities since the negative charge in both is localized on an oxygen atom.
B. Methoxide is more nucleophilic because the nucleophilicity of tert-butoxide is diminished by steric effects.
C. tert-Butoxide is more nucleophilic because it contains three methyl groups which increase the charge on its oxygen by donating electron density.
D. tert-Butoxide is more nucleophilic because it is more basic.
E. none of the above
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