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

Amongst the following which of the above are true for S_N2 reaction?

(i) The rate of reaction is independent of the concentration of the nucleophile

(ii) The nucleophile attacks the carbon atom on the side of the molecule opposite to the group being displaced.

(iii) The reaction proceeds with simultaneous bond formation and bond rupture.

1. (i), (ii)

2. (i), (iii)

3. (i), (ii), (iii)

4. (ii), (iii)

Carbanions initiate:

(1) addition reactions

(2) substitution reaction

(3) both (1) and (2)

(4) none of these

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

Ease of abstraction of hydrogen is greater when attached to:

(1) 1$°$ carbon

(2) 2$°$ carbon

(3) 3$°$carbon

(4) neo carbon

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)

Which step is chain propagation step in the following mechanism?

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

1. (i)

2. (ii)

3. (iii)

4.  (iv)

Carbanion can undergo:

1. rearrangement

2. combination with cation

3. addition to a carbonyl group

4. all of the above are correct

The S_N1 mechanism for substitution reaction by nucleophile is favored by:

1. Low concentration of nucleophile

2. Weak nature of the nucleophile

3. Polar solvent

4. All of the above

S_N1 mechanism for the reaction,

R-X+KOH$\to$ROH+KX follow:

(1) carbocation mechanism

(2) carbanion mechanism

(3) free radical mechanism

(4) either of these