In substitution reactions, dihaloalkane or secondary halogenoalkane give / show:

Explanation

In the case of dihaloalkanes or secondary halogenoalkanes, both SN1 and SN2 mechanisms can occur. However, SN1 mechanism is favored in polar solvents like water or alcohol, while SN1 mechanism is favored in non-polar solvents like ether or hydrocarbons.In the SN1 mechanism, the halogenoalkane undergoes a heterolytic bond cleavage, forming a carbocation intermediate, which is then attacked by the nucleophile. In the SN2 mechanism, the nucleophile attacks the halogenoalkane at the same time as the leaving group departs, leading to inversion of configuration at the carbon center.It is worth noting that the primary halogenoalkanes typically undergo SN2 reactions exclusively, while tertiary halogenoalkanes typically undergo SN1 reactions exclusively.