\({{\text{S}}_{\text{N}}}2\) mechanism involves the back side attack and formation of a transition state, thus less hindered alkyl halide readily undergoes \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. Among the given, \(\mathrm{CH}_{3} \mathrm{Br}\) (methyl bromide) is less hindered, thus it is hydrolysed by \(\mathrm{S}_{\mathrm{N}} 2\) mechanism.
CHXII10:HALOALKANES AND HALOARENES
322587
The rate of \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reaction is maximum when the solvent is
1 \(\mathrm{CH}_{3} \mathrm{OH}\)
2 \(\mathrm{H}_{2} \mathrm{O}\)
3 \({\rm{DMSO}}\)
4 Benzene
Explanation:
Polar aprotic solvents such as DMSO increase the rate of the \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reactions. (DMSO is dimethyl sulphoxide).
CHXII10:HALOALKANES AND HALOARENES
322588
Statement A : \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism is accompanied by racemisation. Statement B : Nucleophile attaches itself on the side opposite to one where halogen atom is present.
1 Statement A is correct but statement B is incorrect.
2 Statement A is incorrect but statement B is correct.
3 Both statements are correct.
4 Both statements are incorrect.
Explanation:
In case of optically active alkyl halides, the product formed as a result of \(\mathrm{S}_{\mathrm{N}} 2\) mechanism has inverted configuration as compared to the reactant. This is because the nucleophile attaches itself on the side opposite to the one where the halogen atom is present.
CHXII10:HALOALKANES AND HALOARENES
322589
Which cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction?
1 \(\mathrm{H}_{2} \mathrm{O}\)
2 \(\mathrm{CN}^{-}\)
3 \(\mathrm{NH}_{2}^{-}\)
4 \(\mathrm{I}^{-}\)
Explanation:
In \(\mathrm{S}_{\mathrm{N}} 2\) reaction, nucleophile transfer electron pair to carbon of substrate, leading to the formation of transition state. \(\mathrm{H}_{2} \mathrm{O}\) is a neutral nucleophile, while \(\mathrm{CN}^{-}, \mathrm{NH}_{2}^{-}\)and \(\mathrm{I}^{-}\)are negatively charged nucleophiles. Thus, \(\mathrm{H}_{2} \mathrm{O}\) cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction.
CHXII10:HALOALKANES AND HALOARENES
322590
Neopentyl alcohol, reacts with \(\mathrm{HX}\) according to:
1 \({{\rm{S}}_{\rm{N}}}1\) mechanism
2 \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism
3 \({{\rm{S}}_{\rm{N}}}{\rm{i}}\)
4 All of these
Explanation:
Neopentyl alcohol, though is a \(1^{\circ}\) alcohol, it undergoes substitution through \(\mathrm{S}_{\mathrm{N}}{ }^{1}\) mechanism because of steric hindrance due to bulky alkyl group.
\({{\text{S}}_{\text{N}}}2\) mechanism involves the back side attack and formation of a transition state, thus less hindered alkyl halide readily undergoes \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. Among the given, \(\mathrm{CH}_{3} \mathrm{Br}\) (methyl bromide) is less hindered, thus it is hydrolysed by \(\mathrm{S}_{\mathrm{N}} 2\) mechanism.
CHXII10:HALOALKANES AND HALOARENES
322587
The rate of \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reaction is maximum when the solvent is
1 \(\mathrm{CH}_{3} \mathrm{OH}\)
2 \(\mathrm{H}_{2} \mathrm{O}\)
3 \({\rm{DMSO}}\)
4 Benzene
Explanation:
Polar aprotic solvents such as DMSO increase the rate of the \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reactions. (DMSO is dimethyl sulphoxide).
CHXII10:HALOALKANES AND HALOARENES
322588
Statement A : \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism is accompanied by racemisation. Statement B : Nucleophile attaches itself on the side opposite to one where halogen atom is present.
1 Statement A is correct but statement B is incorrect.
2 Statement A is incorrect but statement B is correct.
3 Both statements are correct.
4 Both statements are incorrect.
Explanation:
In case of optically active alkyl halides, the product formed as a result of \(\mathrm{S}_{\mathrm{N}} 2\) mechanism has inverted configuration as compared to the reactant. This is because the nucleophile attaches itself on the side opposite to the one where the halogen atom is present.
CHXII10:HALOALKANES AND HALOARENES
322589
Which cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction?
1 \(\mathrm{H}_{2} \mathrm{O}\)
2 \(\mathrm{CN}^{-}\)
3 \(\mathrm{NH}_{2}^{-}\)
4 \(\mathrm{I}^{-}\)
Explanation:
In \(\mathrm{S}_{\mathrm{N}} 2\) reaction, nucleophile transfer electron pair to carbon of substrate, leading to the formation of transition state. \(\mathrm{H}_{2} \mathrm{O}\) is a neutral nucleophile, while \(\mathrm{CN}^{-}, \mathrm{NH}_{2}^{-}\)and \(\mathrm{I}^{-}\)are negatively charged nucleophiles. Thus, \(\mathrm{H}_{2} \mathrm{O}\) cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction.
CHXII10:HALOALKANES AND HALOARENES
322590
Neopentyl alcohol, reacts with \(\mathrm{HX}\) according to:
1 \({{\rm{S}}_{\rm{N}}}1\) mechanism
2 \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism
3 \({{\rm{S}}_{\rm{N}}}{\rm{i}}\)
4 All of these
Explanation:
Neopentyl alcohol, though is a \(1^{\circ}\) alcohol, it undergoes substitution through \(\mathrm{S}_{\mathrm{N}}{ }^{1}\) mechanism because of steric hindrance due to bulky alkyl group.
\({{\text{S}}_{\text{N}}}2\) mechanism involves the back side attack and formation of a transition state, thus less hindered alkyl halide readily undergoes \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. Among the given, \(\mathrm{CH}_{3} \mathrm{Br}\) (methyl bromide) is less hindered, thus it is hydrolysed by \(\mathrm{S}_{\mathrm{N}} 2\) mechanism.
CHXII10:HALOALKANES AND HALOARENES
322587
The rate of \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reaction is maximum when the solvent is
1 \(\mathrm{CH}_{3} \mathrm{OH}\)
2 \(\mathrm{H}_{2} \mathrm{O}\)
3 \({\rm{DMSO}}\)
4 Benzene
Explanation:
Polar aprotic solvents such as DMSO increase the rate of the \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reactions. (DMSO is dimethyl sulphoxide).
CHXII10:HALOALKANES AND HALOARENES
322588
Statement A : \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism is accompanied by racemisation. Statement B : Nucleophile attaches itself on the side opposite to one where halogen atom is present.
1 Statement A is correct but statement B is incorrect.
2 Statement A is incorrect but statement B is correct.
3 Both statements are correct.
4 Both statements are incorrect.
Explanation:
In case of optically active alkyl halides, the product formed as a result of \(\mathrm{S}_{\mathrm{N}} 2\) mechanism has inverted configuration as compared to the reactant. This is because the nucleophile attaches itself on the side opposite to the one where the halogen atom is present.
CHXII10:HALOALKANES AND HALOARENES
322589
Which cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction?
1 \(\mathrm{H}_{2} \mathrm{O}\)
2 \(\mathrm{CN}^{-}\)
3 \(\mathrm{NH}_{2}^{-}\)
4 \(\mathrm{I}^{-}\)
Explanation:
In \(\mathrm{S}_{\mathrm{N}} 2\) reaction, nucleophile transfer electron pair to carbon of substrate, leading to the formation of transition state. \(\mathrm{H}_{2} \mathrm{O}\) is a neutral nucleophile, while \(\mathrm{CN}^{-}, \mathrm{NH}_{2}^{-}\)and \(\mathrm{I}^{-}\)are negatively charged nucleophiles. Thus, \(\mathrm{H}_{2} \mathrm{O}\) cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction.
CHXII10:HALOALKANES AND HALOARENES
322590
Neopentyl alcohol, reacts with \(\mathrm{HX}\) according to:
1 \({{\rm{S}}_{\rm{N}}}1\) mechanism
2 \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism
3 \({{\rm{S}}_{\rm{N}}}{\rm{i}}\)
4 All of these
Explanation:
Neopentyl alcohol, though is a \(1^{\circ}\) alcohol, it undergoes substitution through \(\mathrm{S}_{\mathrm{N}}{ }^{1}\) mechanism because of steric hindrance due to bulky alkyl group.
\({{\text{S}}_{\text{N}}}2\) mechanism involves the back side attack and formation of a transition state, thus less hindered alkyl halide readily undergoes \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. Among the given, \(\mathrm{CH}_{3} \mathrm{Br}\) (methyl bromide) is less hindered, thus it is hydrolysed by \(\mathrm{S}_{\mathrm{N}} 2\) mechanism.
CHXII10:HALOALKANES AND HALOARENES
322587
The rate of \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reaction is maximum when the solvent is
1 \(\mathrm{CH}_{3} \mathrm{OH}\)
2 \(\mathrm{H}_{2} \mathrm{O}\)
3 \({\rm{DMSO}}\)
4 Benzene
Explanation:
Polar aprotic solvents such as DMSO increase the rate of the \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reactions. (DMSO is dimethyl sulphoxide).
CHXII10:HALOALKANES AND HALOARENES
322588
Statement A : \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism is accompanied by racemisation. Statement B : Nucleophile attaches itself on the side opposite to one where halogen atom is present.
1 Statement A is correct but statement B is incorrect.
2 Statement A is incorrect but statement B is correct.
3 Both statements are correct.
4 Both statements are incorrect.
Explanation:
In case of optically active alkyl halides, the product formed as a result of \(\mathrm{S}_{\mathrm{N}} 2\) mechanism has inverted configuration as compared to the reactant. This is because the nucleophile attaches itself on the side opposite to the one where the halogen atom is present.
CHXII10:HALOALKANES AND HALOARENES
322589
Which cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction?
1 \(\mathrm{H}_{2} \mathrm{O}\)
2 \(\mathrm{CN}^{-}\)
3 \(\mathrm{NH}_{2}^{-}\)
4 \(\mathrm{I}^{-}\)
Explanation:
In \(\mathrm{S}_{\mathrm{N}} 2\) reaction, nucleophile transfer electron pair to carbon of substrate, leading to the formation of transition state. \(\mathrm{H}_{2} \mathrm{O}\) is a neutral nucleophile, while \(\mathrm{CN}^{-}, \mathrm{NH}_{2}^{-}\)and \(\mathrm{I}^{-}\)are negatively charged nucleophiles. Thus, \(\mathrm{H}_{2} \mathrm{O}\) cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction.
CHXII10:HALOALKANES AND HALOARENES
322590
Neopentyl alcohol, reacts with \(\mathrm{HX}\) according to:
1 \({{\rm{S}}_{\rm{N}}}1\) mechanism
2 \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism
3 \({{\rm{S}}_{\rm{N}}}{\rm{i}}\)
4 All of these
Explanation:
Neopentyl alcohol, though is a \(1^{\circ}\) alcohol, it undergoes substitution through \(\mathrm{S}_{\mathrm{N}}{ }^{1}\) mechanism because of steric hindrance due to bulky alkyl group.
\({{\text{S}}_{\text{N}}}2\) mechanism involves the back side attack and formation of a transition state, thus less hindered alkyl halide readily undergoes \(\mathrm{S}_{\mathrm{N}} 2\) mechanism. Among the given, \(\mathrm{CH}_{3} \mathrm{Br}\) (methyl bromide) is less hindered, thus it is hydrolysed by \(\mathrm{S}_{\mathrm{N}} 2\) mechanism.
CHXII10:HALOALKANES AND HALOARENES
322587
The rate of \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reaction is maximum when the solvent is
1 \(\mathrm{CH}_{3} \mathrm{OH}\)
2 \(\mathrm{H}_{2} \mathrm{O}\)
3 \({\rm{DMSO}}\)
4 Benzene
Explanation:
Polar aprotic solvents such as DMSO increase the rate of the \(\mathrm{S}_{\mathrm{N}}{ }^{2}\) reactions. (DMSO is dimethyl sulphoxide).
CHXII10:HALOALKANES AND HALOARENES
322588
Statement A : \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism is accompanied by racemisation. Statement B : Nucleophile attaches itself on the side opposite to one where halogen atom is present.
1 Statement A is correct but statement B is incorrect.
2 Statement A is incorrect but statement B is correct.
3 Both statements are correct.
4 Both statements are incorrect.
Explanation:
In case of optically active alkyl halides, the product formed as a result of \(\mathrm{S}_{\mathrm{N}} 2\) mechanism has inverted configuration as compared to the reactant. This is because the nucleophile attaches itself on the side opposite to the one where the halogen atom is present.
CHXII10:HALOALKANES AND HALOARENES
322589
Which cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction?
1 \(\mathrm{H}_{2} \mathrm{O}\)
2 \(\mathrm{CN}^{-}\)
3 \(\mathrm{NH}_{2}^{-}\)
4 \(\mathrm{I}^{-}\)
Explanation:
In \(\mathrm{S}_{\mathrm{N}} 2\) reaction, nucleophile transfer electron pair to carbon of substrate, leading to the formation of transition state. \(\mathrm{H}_{2} \mathrm{O}\) is a neutral nucleophile, while \(\mathrm{CN}^{-}, \mathrm{NH}_{2}^{-}\)and \(\mathrm{I}^{-}\)are negatively charged nucleophiles. Thus, \(\mathrm{H}_{2} \mathrm{O}\) cannot behave as a nucleophile for \(\mathrm{S}_{\mathrm{N}} 2\) reaction.
CHXII10:HALOALKANES AND HALOARENES
322590
Neopentyl alcohol, reacts with \(\mathrm{HX}\) according to:
1 \({{\rm{S}}_{\rm{N}}}1\) mechanism
2 \({{\rm{S}}_{\rm{N}}}{\rm{2}}\) mechanism
3 \({{\rm{S}}_{\rm{N}}}{\rm{i}}\)
4 All of these
Explanation:
Neopentyl alcohol, though is a \(1^{\circ}\) alcohol, it undergoes substitution through \(\mathrm{S}_{\mathrm{N}}{ }^{1}\) mechanism because of steric hindrance due to bulky alkyl group.
