In S_N2 substitution reaction of the type

$R - \mathrm{Br} + {\mathrm{Cl}}^{-} \stackrel{\mathrm{DMF}}{\to }R - \mathrm{Cl} + {\mathrm{Br}}^{-},$

Which one of the following has the highest relative rate ?

(1) ${\mathrm{CH}}_3-{\mathrm{CH}}_2-{\mathrm{CH}}_2\mathrm{Br}$

(2) ${\mathrm{CH}}_3-\underset{\underset{{\mathrm{CH}}_3}{|}}{\mathrm{C}}\mathrm{H}-{\mathrm{CH}}_2\mathrm{Br}$

(3) ${\mathrm{CH}}_3-\underset{\underset{{\mathrm{CH}}_3}{|}}{\overset{\underset{|}{{\mathrm{CH}}_3}}{\mathrm{C}}}-{\mathrm{CH}}_2\mathrm{Br}$

(4) ${\mathrm{CH}}_3{\mathrm{CH}}_2\mathrm{Br}$

Which one is the most reactive toward S_N1 reaction?

1. C₆H₅CH(C₆H₅)Br

2. C₆H₅CH(CH₃)Br

3. C₆H₅C(CH₃)(C₆H₅)Br

4. C₆H₅CH₂Br

The reaction of C₆H₅CH=CHCH₃ with HBr produces


 

The compound that will react most readily with gaseous bromine has the formula ?
(1) C₃H₆

(2) C₂H₂

(3) C₄H₁₀

(4) C₂H₄

Consider the reaction 

CH₃CH₂CH₂Br + NaCN $\to$CH₃CH₂CH₂CN + NaBr

This reaction will be the fastest in

1. ethanol

2. methanol

3. N,N'-dimethylformamide (DMF)

4. water

In the given reaction

the product P is:

1.		2.
3.		4.

Which of the following can be used as the halide component for Friedel-Crafts reaction?

(1) Chlorobenzene

(2) Bromobenzene

(3) Chloroethene

(4) Isopropyl chloride

AgNO₃(aq) gives yellow ppt. with:

(1) KIO₃ (aq)                       

(2) KI (aq)

(3) CHI₃                               

(4) CH₂I₂

Compound (A), C₈H₉Br, gives a white precipitate when warmed with alcoholic AgNO₃. Oxidation of (A) gives an acid (B), C₈H₆O₄. (B) easily forms anhydride on heating. Identify the compound (A).

1. 

2. 

3. 

4. 

Chlorobenzene is prepared commercially by:

1. Grignard reaction

2. Raschig process

3. Wurtz-Fittig reaction

4. Friedel-Crafts reaction