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CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323240 Assertion :
The major products formed by heating $C_{6} H_{5} {CH}_{2} {OCH}_{3}$ with $HI$ are $C_{6} H_{5} {CH}_{2} I$ and ${CH}_{3} OH$ .
Reason :
Benzyl cation is more stable than methyl cation.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
The reaction follows $S_{N} 1$ mechanism. The benzyl cation produced is more stable than methyl carbocation. So the option (1) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323241 Tert-butyl methyl ether on heating with anhydrous $HI$ in ether gives

1

{CH}_{3} OH + {({CH}_{3})}_{3} CI

2

{CH}_{3} I + {({CH}_{3})}_{3} COH

3

{CH}_{3} I + {({CH}_{3})}_{3} CI

4 None of these

Explanation:

Here, ether is the solvent. Being less polar, it favours $S_{N} 2$ reaction and the nucleophile $I^{-}$ attacks $1^{\circ}$ carbon of ${CH}_{3}$ .
supporting img

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323242 $HBr$ reacts with ${CH}_{2} = CH - {OCH}_{3}$ under anhydrous conditions at room temperature to give:

1

H_{3} C - CHBr - {OCH}_{3}

2

{BrCH}_{2} - {CH}_{2} - {OCH}_{3}

3

{CH}_{3} CHO

and

{CH}_{3} Br

4

{BrCH}_{2} CHO

and

{CH}_{3} OH

Explanation:

$\begin{aligned} {CH}_{2} & = CH - {OCH}_{3} + H^{+} \to {CH}_{3} \overset{+}{C} H - {OCH}_{3} + {Br}^{-} \\ \to {CH}_{3} CH (Br) {OCH}_{3} . \end{aligned}$
The formed Carbocation, ${CH}_{3} \overset{+}{C} H - {OCH}_{3}$ is stabilised by resonance with oxygen so its formation is more favourable than $\overset{+}{C} H_{2} {CH}_{2} {OCH}_{3}$ .

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323243 Assertion :
tert-Butyl methyl ether on cleavage with $HI$ at $373 K$ gives tert-butyl iodide and methanol.
Reason :
The reaction occurs by $S_{N} 2$ mechanism.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

If the reaction takes place via an $S_{N} 2$ mechanism, it would lead to the formation of methyl iodide and tert-butyl alcohol due to direct displacement of the leaving group by the nucleophilic alkoxide ion, resulting in inversion of configuration at the carbon center. So the option (3) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323240 Assertion :
The major products formed by heating $C_{6} H_{5} {CH}_{2} {OCH}_{3}$ with $HI$ are $C_{6} H_{5} {CH}_{2} I$ and ${CH}_{3} OH$ .
Reason :
Benzyl cation is more stable than methyl cation.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
The reaction follows $S_{N} 1$ mechanism. The benzyl cation produced is more stable than methyl carbocation. So the option (1) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323241 Tert-butyl methyl ether on heating with anhydrous $HI$ in ether gives

1

{CH}_{3} OH + {({CH}_{3})}_{3} CI

2

{CH}_{3} I + {({CH}_{3})}_{3} COH

3

{CH}_{3} I + {({CH}_{3})}_{3} CI

4 None of these

Explanation:

Here, ether is the solvent. Being less polar, it favours $S_{N} 2$ reaction and the nucleophile $I^{-}$ attacks $1^{\circ}$ carbon of ${CH}_{3}$ .
supporting img

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323242 $HBr$ reacts with ${CH}_{2} = CH - {OCH}_{3}$ under anhydrous conditions at room temperature to give:

1

H_{3} C - CHBr - {OCH}_{3}

2

{BrCH}_{2} - {CH}_{2} - {OCH}_{3}

3

{CH}_{3} CHO

and

{CH}_{3} Br

4

{BrCH}_{2} CHO

and

{CH}_{3} OH

Explanation:

$\begin{aligned} {CH}_{2} & = CH - {OCH}_{3} + H^{+} \to {CH}_{3} \overset{+}{C} H - {OCH}_{3} + {Br}^{-} \\ \to {CH}_{3} CH (Br) {OCH}_{3} . \end{aligned}$
The formed Carbocation, ${CH}_{3} \overset{+}{C} H - {OCH}_{3}$ is stabilised by resonance with oxygen so its formation is more favourable than $\overset{+}{C} H_{2} {CH}_{2} {OCH}_{3}$ .

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323243 Assertion :
tert-Butyl methyl ether on cleavage with $HI$ at $373 K$ gives tert-butyl iodide and methanol.
Reason :
The reaction occurs by $S_{N} 2$ mechanism.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

If the reaction takes place via an $S_{N} 2$ mechanism, it would lead to the formation of methyl iodide and tert-butyl alcohol due to direct displacement of the leaving group by the nucleophilic alkoxide ion, resulting in inversion of configuration at the carbon center. So the option (3) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323240 Assertion :
The major products formed by heating $C_{6} H_{5} {CH}_{2} {OCH}_{3}$ with $HI$ are $C_{6} H_{5} {CH}_{2} I$ and ${CH}_{3} OH$ .
Reason :
Benzyl cation is more stable than methyl cation.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
The reaction follows $S_{N} 1$ mechanism. The benzyl cation produced is more stable than methyl carbocation. So the option (1) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323241 Tert-butyl methyl ether on heating with anhydrous $HI$ in ether gives

1

{CH}_{3} OH + {({CH}_{3})}_{3} CI

2

{CH}_{3} I + {({CH}_{3})}_{3} COH

3

{CH}_{3} I + {({CH}_{3})}_{3} CI

4 None of these

Explanation:

Here, ether is the solvent. Being less polar, it favours $S_{N} 2$ reaction and the nucleophile $I^{-}$ attacks $1^{\circ}$ carbon of ${CH}_{3}$ .
supporting img

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323242 $HBr$ reacts with ${CH}_{2} = CH - {OCH}_{3}$ under anhydrous conditions at room temperature to give:

1

H_{3} C - CHBr - {OCH}_{3}

2

{BrCH}_{2} - {CH}_{2} - {OCH}_{3}

3

{CH}_{3} CHO

and

{CH}_{3} Br

4

{BrCH}_{2} CHO

and

{CH}_{3} OH

Explanation:

$\begin{aligned} {CH}_{2} & = CH - {OCH}_{3} + H^{+} \to {CH}_{3} \overset{+}{C} H - {OCH}_{3} + {Br}^{-} \\ \to {CH}_{3} CH (Br) {OCH}_{3} . \end{aligned}$
The formed Carbocation, ${CH}_{3} \overset{+}{C} H - {OCH}_{3}$ is stabilised by resonance with oxygen so its formation is more favourable than $\overset{+}{C} H_{2} {CH}_{2} {OCH}_{3}$ .

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323243 Assertion :
tert-Butyl methyl ether on cleavage with $HI$ at $373 K$ gives tert-butyl iodide and methanol.
Reason :
The reaction occurs by $S_{N} 2$ mechanism.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

If the reaction takes place via an $S_{N} 2$ mechanism, it would lead to the formation of methyl iodide and tert-butyl alcohol due to direct displacement of the leaving group by the nucleophilic alkoxide ion, resulting in inversion of configuration at the carbon center. So the option (3) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323240 Assertion :
The major products formed by heating $C_{6} H_{5} {CH}_{2} {OCH}_{3}$ with $HI$ are $C_{6} H_{5} {CH}_{2} I$ and ${CH}_{3} OH$ .
Reason :
Benzyl cation is more stable than methyl cation.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

supporting img
The reaction follows $S_{N} 1$ mechanism. The benzyl cation produced is more stable than methyl carbocation. So the option (1) is correct.

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323241 Tert-butyl methyl ether on heating with anhydrous $HI$ in ether gives

1

{CH}_{3} OH + {({CH}_{3})}_{3} CI

2

{CH}_{3} I + {({CH}_{3})}_{3} COH

3

{CH}_{3} I + {({CH}_{3})}_{3} CI

4 None of these

Explanation:

Here, ether is the solvent. Being less polar, it favours $S_{N} 2$ reaction and the nucleophile $I^{-}$ attacks $1^{\circ}$ carbon of ${CH}_{3}$ .
supporting img

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323242 $HBr$ reacts with ${CH}_{2} = CH - {OCH}_{3}$ under anhydrous conditions at room temperature to give:

1

H_{3} C - CHBr - {OCH}_{3}

2

{BrCH}_{2} - {CH}_{2} - {OCH}_{3}

3

{CH}_{3} CHO

and

{CH}_{3} Br

4

{BrCH}_{2} CHO

and

{CH}_{3} OH

Explanation:

$\begin{aligned} {CH}_{2} & = CH - {OCH}_{3} + H^{+} \to {CH}_{3} \overset{+}{C} H - {OCH}_{3} + {Br}^{-} \\ \to {CH}_{3} CH (Br) {OCH}_{3} . \end{aligned}$
The formed Carbocation, ${CH}_{3} \overset{+}{C} H - {OCH}_{3}$ is stabilised by resonance with oxygen so its formation is more favourable than $\overset{+}{C} H_{2} {CH}_{2} {OCH}_{3}$ .

CHXII11:ALCOHOLS, PHENOLS AND ETHERS

323243 Assertion :
tert-Butyl methyl ether on cleavage with $HI$ at $373 K$ gives tert-butyl iodide and methanol.
Reason :
The reaction occurs by $S_{N} 2$ mechanism.

1 Both Assertion and Reason are correct and Reason is the correct explanation of the Assertion.

2 Both Assertion and Reason are correct but Reason is not the correct explanation of the Assertion.

3 Assertion is correct but Reason is incorrect.

4 Assertion is incorrect but Reason is correct.

Explanation:

If the reaction takes place via an $S_{N} 2$ mechanism, it would lead to the formation of methyl iodide and tert-butyl alcohol due to direct displacement of the leaving group by the nucleophilic alkoxide ion, resulting in inversion of configuration at the carbon center. So the option (3) is correct.

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