Arrange the following compounds in order of d | vedclass

Name: Exam Paper Generator | JEE NEET Paper Generator | Vedclass
Brand: Vedclass
Rating: 5 (35 reviews)

Question

(B) The rate of $S_N1$ reaction depends on the stability of the carbocation intermediate formed after the departure of the leaving group $(Br^-)$.In a

Vedclass · Accepted Answer

$iv > iii > ii > i$

Vedclass · Answer

(B) The rate of $S_N1$ reaction depends on the stability of the carbocation intermediate formed after the departure of the leaving group $(Br^-)$.In all these cases,a benzylic carbocation is formed: $Ar-CH_2^+$.The stability of the benzylic carbocation is increased by electron-donating groups $(EDG)$ at the para position due to the $+I$ effect and hyperconjugation.The order of electron-donating ability of the alkyl groups is: isopropyl $(>CH(CH_3)_2)$ > ethyl $(-CH_2CH_3)$ > methyl $(-CH_3)$ > hydrogen $(-H)$.- Compound (iv) has an isopropyl group,which provides the strongest $+I$ effect and hyperconjugation,making the carbocation most stable.- Compound (iii) has an ethyl group,which is the next most effective electron donor.- Compound (ii) has a methyl group,which is the least effective electron donor among the alkyl groups.- Compound $(i)$ has no electron-donating group.Therefore,the stability of the carbocations and the rate of $S_N1$ reaction follow the order: $(iv) > (iii) > (ii) > (i)$.

Reaction	Product
$I$. $RX + AgCN$	$RNC$
$II$. $RX + KCN$	$RCN$
$III$. $RX + KNO_2$	$RONO$
$IV$. $RX + AgNO_2$	$RNO_2$

Arrange the following compounds in order of decreasing rate of hydrolysis for $S_N1$ reaction:
$(i)$ $C_6H_5CH_2Br$
(ii) $p-CH_3-C_6H_4-CH_2Br$
(iii) $p-CH_3CH_2-C_6H_4-CH_2Br$
(iv) $p-(CH_3)_2CH-C_6H_4-CH_2Br$

Similar Questions

From each of the following pairs,select the compound that will react faster with sodium iodide in acetone:
Pair-$A$: $(1) \, 2-$Chloropropane,$(2) \, 2-$Bromopropane
Pair-$B$: $(3) \, 1-$Bromobutane,$(4) \, 2-$Bromobutane

Which of the following pairs is/are correctly matched?

Reaction Product

$I$. $RX + AgCN$ $RNC$

$II$. $RX + KCN$ $RCN$

$III$. $RX + KNO_2$ $RONO$

$IV$. $RX + AgNO_2$ $RNO_2$

How many minimum numbers of $C$-atom containing monohaloalkane shows optical isomerism?

Consider the following reaction and select the best choice that represents the product:

In which of the following cases is the yield via $S_{N}2$ mechanism maximum?

Vedclass Test Series

Exam Paper Generator

Online Exam Module

Arrange the following compounds in order of decreasing rate of hydrolysis for $S_N1$ reaction:$(i)$ $C_6H_5CH_2Br$(ii) $p-CH_3-C_6H_4-CH_2Br$(iii) $p-CH_3CH_2-C_6H_4-CH_2Br$(iv) $p-(CH_3)_2CH-C_6H_4-CH_2Br$