(i)\[{{(C{{H}_{3}})}_{3}}CBr.\] |
(ii) \[{{({{C}_{6}}{{H}_{5}})}_{2}}CHBr\] |
(iii) \[{{({{C}_{6}}{{H}_{5}})}_{2}}C(C{{H}_{3}})Br\] |
(iv) \[{{(C{{H}_{3}})}_{2}}CHBr\] |
(v) \[{{C}_{2}}{{H}_{5}}Br\] |
A) (v)>(iv)>(i)>(ii)>(iii)
B) (ii)>(i)>(iii)>(v)>(iv)
C) (i)>(iii)>(v)>(ii)>(iv)
D) (v)>(i)>(ii)>(iv)>(iii)
E) (iii)>(ii)>(i)>(iv)>(v)
Correct Answer: E
Solution :
\[{{S}_{N}}1\] (Unimolecular nucleophilic substitution reactions) \[Rate\propto (substrate)\] Rate of determining step in the formation of carbocation depends on the stability of carbocation formed. The stability of carbocations follow the order- \[{{({{C}_{6}}{{H}_{5}})}_{2}}{{C}^{+}}(C{{H}_{3}})>{{({{C}_{6}}{{H}_{5}})}_{2}}\overset{+}{\mathop{C}}\,H>\] \[{{(C{{H}_{3}})}_{2}}\overset{+}{\mathop{C}}\,H>C{{H}_{3}}CH_{2}^{+}\] \[\because \]Order of\[{{S}_{N}}1\]reactivity is \[{{({{C}_{6}}{{H}_{5}})}_{2}}C(C{{H}_{3}})Br>{{({{C}_{6}}{{H}_{5}})}_{2}}CHBr>\] \[{{(C{{H}_{3}})}_{3}}CBr>{{(C{{H}_{3}})}_{2}}\overset{+}{\mathop{C}}\,HBr>{{C}_{2}}{{H}_{5}}Br\] ie, \[iii>ii>i>iv>v\]You need to login to perform this action.
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