SCIENCE
CHEMISTRY
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
1-iodobutane
|
|
|
1-chlorobutane
|
|
|
2-chloro-2-methylpropane
|
|
|
2-iodo-2-methylpropane
|
Detailed explanation-1: -The answer is option c. Tertiary alkyl halides react faster than primary alkyl halides in SN1 S N 1 reactions.
Detailed explanation-2: -Heavily halogenated halogenoalkanes are used in some fire extinguishers. We find that the 1-iodobutane reacts fastest as the C-I bond is the weakest of the C-Hal bonds and so breaks easiest and fastest.
Detailed explanation-3: -However, the fastest reaction is with an iodoalkane. In these reactions, bond strength is the main factor deciding the relative rates of reaction. You would need to keep the halogen atom constant.
Detailed explanation-4: -Tertiary haloakanes react via an sN1 mechanism that has a much lower activation energy than the sN2 mechanism with the high energy transition state. Hence tertiary haloalkanes react faster then secondary, which in turn react faster than primary.