HALOALKANE

Haloalkane is a polar molecule that undergoes nucleophilic substitution through S_N1 and S_N2. Arrange the following haloalkanes in order of increasing rate of unimolecular nucleophilic substitution reaction:

I. 2-chloro-2-methylpropane

II. 2-chlorobutane

III. 1-chlorobutane

• I< II < III

• I< III < II

• III< I < II

• III< II < I

Compound C easily undergoes hydrolysis to form compound D, which forms 2-methylpropene when heated with concentrated sulphuric acid. Using the information above, proposed the structural formula for compound C

• CH₃CH₂CH(Br)CH₃

• CH₃CH₂CH₂CH(Br)CH₃

• CH₃CH₂(CH₃)CH₂Br

• (CH₃)₂C(Br)CH₃

Which of the following compounds is the rate of alkaline hydrolysis that is independent of the concentration of the hydroxide ion?

• CH₃CH₂CH₂CH₂Cl

• CH₃CH(Br)CH₃

• C₆H₅CH₂CH₂I

• (CH₃)₃CBr

Which of the following is a chiral molecule?

• CH₂BrI

• CH₃CBr₂Cl

• (CH₃)₂CHCl

• CH₃CHBrCH₂CH₃

Alkenes react with hydrogen halides, HX to formed haloalkane. In the reaction;

I. the pi electrons are used to form a bond with the hydrogen atom from HX

II. the intermediate product is carbocation

III. the rate of reaction increases in the order: HF, HCl, HBr, HI

• I only

• I and II only

• II and III only

• I, II and III

Which of the following species is/are nucleophile(s)?

I. OH^–

II. H₂O

III. R₃C^–

• I only

• I and II only

• II and III only

• I, II and III

A is a secondary haloalkane with formula C₅H₁₁Br and optically active. Identify A.

• CH₃CH₂CH₂CH₂CH₂Br

• CH₃CH(Br)CH₂CH₂CH₃

• (CH₃)₂C(Br)CH₂CH₃

• (CH₃)₂C(Br)C(CH₃)₂CH₂CH₃

Name compound B below according to IUPAC nomenclature.

• 4-chloro-5-bromo-6-phenylhexane

• 2-bromo-3-chloro-1-phenylhexane

• 3-bromo-1-phenyl-2-bromohexane

• 5-bromo-4-chloro-6-phenylhexane

Which is a primary alkyl halide?

• CH₃CH(Br)CH₃

• C₆H₅Cl

• CH₃CH(CH₂Br)CH₃

• CH₃CH₂C(Cl)₂CH₃

The number of isomers (including structural and stereoisomers) of C₄H₉Cl is

• 2

• 3

• 4

• 5