Which of the following alkyl halide undergo rearrangement in S_N1 reaction?

1. $\begin{array}{ccccccc}{\mathrm{CH}}_3& -& \underset{{\mathrm{CH}}_3}{\underset{|}{\stackrel{{\mathrm{CH}}_3}{\stackrel{|}{\mathrm{C}}}}}& -& \underset{\mathrm{I}}{\underset{|}{\mathrm{CH}}}& -& {\mathrm{CH}}_3\end{array}$

2.  

3.  

4. All of these

Which compound undergoes nucleophilic substitution with NaCN at the fastest rate ?

1.  

2.  

3.  

4.  

Rank the following in order of decreasing rate of solvolysis with aqueous ethanol (fastest $\to$slowest)
 

a.		b.
c.

1. b>a>c

2. a>b>c

3. b>c>a

4. a>c>b


   

Which of the following reactant will not favour S_N2 nucleophilic substitution reaction?

1. 

2. Ph-Br

3. ${\mathrm{CH}}_3-\underset{{\mathrm{CH}}_3}{\overset{{\mathrm{CH}}_3}{\underset{\left|}{\overset{\right|}{\mathrm{C}}}}}-{\mathrm{CH}}_2-\mathrm{Br}$

4. All of the above

$\stackrel{\mathrm{NBS}}{\to }$(A)$\stackrel{{\mathrm{CH}}_3\mathrm{SNa}}{\to }$(B), Product (B) is:

1.

2.  

3. 

4. None of these

What is the major product of the following reaction?

${\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-{\mathrm{CH}}_2-\mathrm{OH} \underset{\mathrm{excess}}{\overset{\mathrm{HBr}}{\to }} \mathrm{Product}$

1.  ${\mathrm{CH}}_3-\stackrel{\mathrm{Br}}{\stackrel{|}{\mathrm{CH}}}-{\mathrm{CH}}_2-\mathrm{Br}$

2.  ${\mathrm{H}}_2\mathrm{C}=\mathrm{CH}-{\mathrm{CH}}_2-\mathrm{Br}$

3.  ${\mathrm{CH}}_3-\stackrel{\mathrm{Br}}{\stackrel{|}{\mathrm{CH}}}-{\mathrm{CH}}_2-\mathrm{OH}$

4.  ${\mathrm{CH}}_3-\stackrel{OH}{\stackrel{|}{\mathrm{CH}}}-{\mathrm{CH}}_2-\mathrm{OH}$

S_N1 and S_N2 products are the same with (excluding stereoisomer):-

1.  
 2.  
3.  

4. 

Consider the nucleophilic attacks given below. Select in each pair that shows the greater S_N2 reaction rate.

(A)  

(B) $H_{3}C-Br+{}_{-}SH or H_{3}C-Br+C{H}_{3}SH$
$\left(iii\right) \left(iv\right)$

(C)  

(D)  


     A   B    C     D
1.  II   IV   VI   VIII
2.  II   III   V    VIII
3.  I    III   V    VIII
4.  I    III   V    VII 

Addition of KI accelerates the hydrolysis of primary alkyl halides because:

1. KI is soluble in organic solvents

2. the iodide ion is a weak base and a poor leaving group

3. the iodide ion is a strong base

4. the iodide ion is a powerful nucleophile as well as a good leaving group