Which one of the following undergoes nucleophilic aromatic substitution at the fastest rate?
(1) 

(2) 

(3) 

(4) 

Many organic compounds are prepared by using PCl₅ because:

(1) OH group of alcohol is easily replaced by chlorine atom

(2) chlorines are added to the unsaturated compounds

(3) it removes water from organic compounds

(4) phosphorus atoms are entered in the alcohol

identify the product in the given reaction:

${\mathrm{CH}}_3-\mathrm{CH}={\mathrm{CH}}_2+\mathrm{NOCl}\to \mathrm{product}$

1. ${\mathrm{CH}}_3\mathrm{CHCl}·\mathrm{CH}2·\mathrm{NO}$

2. ${\mathrm{CH}}_3\mathrm{CH}\left(\mathrm{NO}\right)·{\mathrm{CH}}_2\mathrm{Cl}$

3. ${\mathrm{CH}}_3\mathrm{CHCH}\left(\mathrm{Cl}\right)\left(\mathrm{NO}\right)$

4. ${\mathrm{CH}}_2\left(\mathrm{NO}\right)·{\mathrm{CH}}_2·{\mathrm{CH}}_2\mathrm{Cl}$

Common oxidizing agents used in organic chemistry are;

1. Fenton's reagent

2. osmium tetroxide

3. acidified KMnO₄

4. all are correct

 3-methyl-2-pentene on reaction with HOCl gives:

1. 

2. 

3. 

4. 

The hydrolysis of alkyl halides by aqueous NaOH is best termed as:

(1) electrophilic substitution reaction

(2) electrophilic addition reaction

(3) nucleophilic addition reaction

(4) nucleophilic substitution reaction

"The negative part of the addendum adds on the carbon atom joined to the least number of hydrogen atoms." This statement is called as:

(1) Markownikoff's rule

(2) Peroxide effect

(3) Baeyer's strain theory

(4) Thiele's theory

Heterolysis of propane gives:

(1) Methyl and ethyl free radicals

(2) Methylium cation and Ethyl anion

(3) Methyl anion and Ethylium cation

(4) Methylium and Ethylium cations

Dehydrogenation of ethanol to give ethanal is:$\left(1\right) \mathrm{additional} \mathrm{reaction}$
$\left(2\right) \mathrm{\alpha }-\mathrm{\alpha } \mathrm{elimination} \mathrm{reaction}$
$\left(3\right) \mathrm{\alpha }-\mathrm{\beta } \mathrm{elimination} \mathrm{reaction}$
$\left(4\right) \mathrm{\alpha }-\mathrm{\gamma } \mathrm{elimination} \mathrm{reaction}$

Which step is the chain termination step in the following mechanism?

$\left(\mathrm{i}\right) {\mathrm{Cl}}_2\stackrel{h\nu }{\to }{\mathrm{Cl}}^{\bullet }+{\mathrm{Cl}}^{\bullet }$
$\left(\mathrm{ii}\right) {\mathrm{Cl}}^{\bullet }+ {\mathrm{CH}}_4\to \stackrel{\bullet }{{\mathrm{CH}}_3}+ \mathrm{HCl}$
$\left(\mathrm{iii}\right)\stackrel{\bullet }{\mathrm{C}}{\mathrm{H}}_3+{\mathrm{Cl}}_2\to {\mathrm{CH}}_3\mathrm{Cl}+{\mathrm{Cl}}^{\bullet }$
$\left(\mathrm{iv}\right){\mathrm{Cl}}^{\bullet }+\stackrel{\bullet }{\mathrm{C}}{\mathrm{H}}_3\to {\mathrm{CH}}_3\mathrm{Cl}$

1. (i)

2. (ii)

3. (iii)

4. (iv)