Alkyl halides are prepared from alcohols by treating with

1.  HCl + ZnCl22. Red P + Br23.  H2SO4  + Kl4.  All of the above 


(a) Alcohol when reacted with HCI + ZnCl2, then formation of alkyl halide will occur,

ROH+ CHl ZnCl2 RCl + H2O
                                (Alkyl halide)

(b) Alcohol when reacted with red P and X, then formation of alkyl halide product will occur.

    ROHRed P/Br    RX
                                    (Akyl halide)

(c) Alcohols when reacted with H2SO4 and KI then H2SO4, oxidises KI to l2 and does not

form Hl. therefore, alkyl iodide will not produce if the alcohols are treated with

H2SO4 + Kl.