Mechanism of SN & E Reactions in Alkyl Halides

Which of the following factors influence whether a reaction will proceed by

an SN¹, SN², E¹, or E² mechanism?

• pH, pressure, time
• Nature of the substrate, strength of the nucleophile/base, solvent, and reaction conditions.
• Temperature, concentration, catalyst
• Enzyme, pH, concentration

Which compound reacts most rapidly by an SN¹ mechanism?

• terbutyl chloride

• sec butyl chloride

• butyl chloride

• propyl chloride

Which of the following compounds would react most rapidly in an SN²

reaction?

• CH₃CH₂I

• CH₂=CH–I

• (CH₃)₂CHI

• (CH₃)₃CI

Which of the following best describes the carbon-chlorine bond of an alkyl

chloride?

• nonpolar; no dipole

• polar; δ⁺ at carbon and δ^– at chlorine

• polar; δ^– at carbon and δ⁺ at chlorine

• ionic

Which of the following best describes the carbon-magnesium bond of the Grignard reagent?

• nonpolar; no dipole

• polar; δ⁺ at carbon and δ^– at magnesium

• polar; δ^– at carbon and δ⁺ at magnesium

• ionic

Which of the following is a secondary alkyl halide?

• CH₃Br

• (CH₃)₂CHCH₂Br

• (CH₃)₂CHBr

• (CH₃)₃CBr

Which of the following is not correct concerning substitution and elimination

reactions of alkyl halides?

• (a) The electrophile replaces the leaving group.

• (b) Compounds containing electron-donating groups bonded to an sp3 hybridized

  carbon undergo substitution and elimination reactions.

• (c) The electronegative atom is replaced by another atom or group in substitution

  reactions.

• (a) and (b)

Which of the following statements concerning SN² reactions of alkyl halides

is not correct?

• The rate of reaction depends on the concentration of the nucleophile.

• All alkyl iodides react more rapidly than all alkyl chlorides.

• The rate of reaction of a particular alkyl bromide depends on the steric

  accessibility of the carbon of the C-Br bond.

• The rate of reaction depends on the concentration of the alkyl halide.

The phenomenon of inversion takes places in which reaction of alkyl halide?

• SN¹ reaction

• E¹ reaction

• SN² reaction

• E² reaction

The phenomenon of inversion in SN² reactions of alkyl halide is due to?

• Steric hindrance of the alkyl halide
• Electrophilic attack of the nucleophile
• Backside attack of the nucleophile
• Frontside attack of the nucleophile