(i) PCl5 (Phosphorous penta chloride) is used to convert alcohol to alkyl halide.
CH3−CH2−OH Ethyl alcohol +PCl5Δ−→CH3−CH2−Cl Ethyl chloride+HCl+POCl3
(ii) (CH3−C|| O −)2O (Acetic anhydride) is used to convert alcohols to esters.
CH3−CH2−OH+(CH3−C|| O −)2OH+−−→CH3−C|| O −O−CH2−CH3+CH3−C|| O −OH