The correct order of rates of addition of Br_ | vedclass

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(A) The addition of $Br_2/	ext{water}$ to an alkene is an electrophilic addition reaction. The rate-determining step involves the formation of a carb

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$C > D > A > B$

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(A) The addition of $Br_2/	ext{water}$ to an alkene is an electrophilic addition reaction. The rate-determining step involves the formation of a carbocation intermediate.Electron-donating groups (like alkyl groups) increase the electron density of the double bond and stabilize the carbocation intermediate,thereby increasing the rate of reaction.Electron-withdrawing groups (like $-NO_2$) decrease the electron density of the double bond and destabilize the carbocation intermediate,thereby decreasing the rate of reaction.Comparing the substituents:$1$. $CH_3-CH=CH_2$ $(D)$: Has one methyl group (+$I$ effect),stabilizing the carbocation.$2$. $CH_3-CH_2-CH=CH_2$ $(C)$: Has an ethyl group (+$I$ effect),which is slightly more effective than methyl at stabilizing,but steric factors and hyperconjugation make $D$ and $C$ very reactive.$3$. $CH_2=CH_2$ $(A)$: No substituents.$4$. $CH_2=CH-NO_2$ $(B)$: The $-NO_2$ group is a strong electron-withdrawing group (-$I$ and -$M$ effect),making it the least reactive.Thus,the correct order of reactivity is $C > D > A > B$.

The correct order of rates of addition of $Br_2/\text{water}$ to the following alkenes is:
[$A$] $CH_2=CH_2$
[$B$] $CH_2=CH-NO_2$
[$C$] $CH_3-CH_2-CH=CH_2$
[$D$] $CH_3-CH=CH_2$

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The correct order of rates of addition of $Br_2/\text{water}$ to the following alkenes is:[$A$] $CH_2=CH_2$[$B$] $CH_2=CH-NO_2$[$C$] $CH_3-CH_2-CH=CH_2$[$D$] $CH_3-CH=CH_2$