Which reaction converts an alkane to a haloalkane?

The reaction that converts an alkane to a haloalkane involves a substitution reaction using bromine (Br) in the presence of ultraviolet (UV) light. During this type of reaction, the UV light provides the energy necessary to break the bromine bond, generating bromine radicals. These bromine radicals then react with the alkane, substituting one of the hydrogen atoms in a process known as free radical halogenation. This results in the formation of a haloalkane, where a bromine atom replaces a hydrogen atom.

The other options do not serve this purpose. For instance, an addition reaction involving bromine (Br2) adds the bromine across a double bond, which does not apply to alkanes since they lack double bonds. An oxidation reaction with KMnO4 is typically used to oxidize alcohols or alkenes rather than converting alkanes to haloalkanes. Lastly, polymerization reactions involve the joining of monomers to form a polymer, which is unrelated to the substitution of hydrogen in alkanes. Thus, the substitution reaction with bromine and UV light is the correct process for transforming an alkane into a haloalkane.