(IV)only
(III)and(IV)only
(I),(III)and(IV)only
(I)and(II)only
The reactions (I), (III) and (IV) only can be used for the preparation of alkyl halides. Alkyl halide is prepared by the reaction of an alcohol with HCl in which the -OH group is replaced with Cl. Primary and secondary alcohols require a catalyst such as anhydrous zinc chloride. Tertiary alcohols do not require such a catalyst as they are more reactive.