Question

General formula of alkenes and alkyl radicals are respectively?
(A) ${ C }_{ n }{ H }_{ 2n } and { C }_{ n }{ H }_{ 2n+1 }$
(B) ${ C }_{ n }{ H }_{ 2n } and { C }_{ n }{ H }_{ 2n+2 }$
(C) ${ C }_{ n }{ H }_{ 2n-1} and { C }_{ n }{ H }_{ 2n }$
(D) ${ C }_{ n }{ H }_{ 2n+1 } and { C }_{ n }{ H }_{ 2n+2 }$

Answer 1

Hint: A chemical species that contains an unpaired electron is called a radical. Although free radicals contain unpaired electrons, they may be electrically neutral, due to their odd electrons; free radicals are usually highly reactive.

Complete step by step answer:
Generally free radicals also carry free electrons, to give ordinary molecules. Few free radicals are stabilized by their peculiar structures. i.e. they exist for appreciable lengths of time, and when given the right conditions.

In simple words alkyl radicals are carbon chains that have lost one hydrogen.
Generally the alkyl group is a type of functional group that has a carbon and hydrogen atom present in its structure. The general formula for an alkyl group is ${ C }_{ n }{ H }_{ 2n+1 }$, where n represents a number or integer.
The simplest alkyl group is the methyl radical, ${ CH }_{ 3 }$ which has one hydrogen atom less than methane, ${ CH }_{ 4 }$.
Free radicals on tertiary carbons are more stable than secondary and primary because the radical is stabilized through electronic effects of the other groups attached and in this case it would basically be hyperconjugation (the delocalization of electrons with the participation of bonds of primarily sigma character).

Alkene radical, generally when HBr is added to an alkene in the absence of peroxides it obeys Markovnikov’s rule (states that the addition of a protic acid HX to an asymmetric alkene, the acid hydrogen (H) gets attached to the carbon with more hydrogen substitutes and the halide (X) group gets attached to the carbon with more alkyl substituents). With a general formula ${ C }_{ n }{ H }_{ 2n }$.
When HBr reacts with unsymmetrical alkene in the presence of peroxides or oxygen, HBr adds in the opposite direction which is predicted by Markovnikov’s rule.

Therefore, General formula of alkenes and alkyl radicals are respectively ${ C }_{ n }{ H }_{ 2n }$ and ${ C }_{ n }{ H }_{ 2n+1 }$

Note: Free radicals play an important role in combustion, atmospheric chemistry, polymerization, biochemistry and many other chemical processes. They also play a key role in the intermediary metabolism of various biological compounds.