Explain how many types of organic reactlons are possible.

Explanation

Organic reactions are mainly classified into four types known as i) Addition reaction ii) Subsituation reaction iii) Elimination reaction iv) Molecular rearrangements.
I ) Addition reaction : In these the reagent and the substract cobine together to give a single product.
`e.g: CH _(2) = CH _(2) + Br to underset( Br ) underset( |) (CH _(2)) - underset( Br) underset(|) ( CH _(2))`
Depending on the reagent added in the slow ate determining step, addition reactions are again
a) Electrophilic classified additon reactions b) Nu leophilic additon reactions c) Free radical addition reactions.
ii) Substitution reactions : In these reactions on atom or a group of a substrate species is replaced by another atom or group. These aer again classified as a) Electrophilic substitution b) Nucleophilic substitution and c) Free radical substitution reactions on the basis of the reagent involved in the rate determining step.
`e.g.: bar O H _((aq)) + R - X to HO - R + bar X _((aq))`
(iii) Elimination reactions: In these reactions two or more atoms or groups of an organic substrate are removed to form multiple bonds.
`H - underset( N) underset( |) overset( H) overset( |) (C ) - - underset( H) underset( |) overset(X) overset( |) (C ) - H + KOH _(atc) to underset( H ) underset(|) overset( H) overset( |) (C)=underset( H ) underset(|) overset( H) overset( |) (C)+ KX + H _(2)O`
(iv) Molecular rearrangements: Here one organic species (generally less stable) rearranges to other species ( generally more stable). For example. Fries rearrangement.