31. Replacement $$Cl$$ of chlorobenzene to give phenol requires drastic conditions but chlorine of 2, 4-dinitro chlorobenzene is readily replaced. This is because
A
$$N{O_2}$$ makes the ring electron rich at $$ortho$$ and $$para$$ - positions
B
$$N{O_2}$$ withdraw electrons from $$meta$$ - position
C
$$N{O_2}$$ donates electrons at $$meta$$ - position
D
$$N{O_2}$$ withdraw electrons from $$ortho/ para$$ - positions
Answer :
$$N{O_2}$$ withdraw electrons from $$ortho/ para$$ - positions
32. Elimination of bromine from 2 - bromobutane results in the formation of -
A
Predominantly 2 - butyne
B
Predominantly 1 - butene
C
Predominantly 2 - butene
D
equimolar mixture of 1 and 2 - butene
Answer :
Predominantly 2 - butene
33. Which one is a nucleophilic substitution reaction among the following?
A
B
C
D
Answer :
34. Which of the following reactions will not result in the formation of carbon-carbon bonds?
A
Reimer-Tiemann reaction
B
Cannizaro reaction
C
Wurtz reaction
D
Friedel-Crafts’s acylation
Answer :
Cannizaro reaction
35. The compound formed on heating chlorobenzene with chloral in the presence of concentrated sulphuric acid, is
A
freon
B
$$DDT$$
C
gammexene
D
hexachloroethane
Answer :
$$DDT$$
36. 2-bromopentane is heated with potassium ethoxide in ethanol. The major product obtained is
A
2 - ethoxypentane
B
pentene - 1
C
$$trans$$ - pentene - 2
D
$$cis$$ - pentene - 2
Answer :
$$trans$$ - pentene - 2
37. Which chloro derivative of benzene among the following would undergo hydrolysis most readily with aq. $$NaOH$$ to furnish the corresponding hydroxy derivative?
A
B
C
D
Answer :
38.
For the following reactions,
$$\left( {\text{i}} \right)\,C{H_3}C{H_2}C{H_2}Br + KOH \to $$ $$C{H_3}CH = C{H_2} + KBr + {H_2}O$$
Which of the following statements is correct?
A
(i) is elimination reaction, (ii) is substitution and (iii) is addition reaction
B
(i) is elimination, (ii) and (iii) are substitution reactions
C
(i) is substitution, (ii) and (iii) are addition reactions
D
(i) and (ii) are elimination reactions and (iii) is addition reaction
Answer :
(i) is elimination reaction, (ii) is substitution and (iii) is addition reaction
39.
The major product of the following reaction is -
A
B
C
D
Answer :
is a highly polar aprotic solvent.
40. A solution of (+) - 2 - chloro - 2 - phenylethane in toluene tacemises slowly in the presence of small amount of $$SbC{l_5},$$ due to the formation of
A
carbanion
B
carbene
C
free-radical
D
carbocation
Answer :
carbocation
