Out of HCl and `SOCl_2` which is preferred for converting ethanol into chloroethane ? Explain.

Explanation

`SOCl_2` is preferred because when `SOCl_2` react with ethylene alcohol, it will give chloroethane and other product such as `SO_2` and HCl gases. These gases produce iti this reaction will escape easily and give major product as chloroethane but reaction with HCl, no such type of gases produce. Hence, `SOCl_2` is preferred.
`underset("Ethoanol")(C_2H_5OH + SOCl_2) overset("Pyridine")to underset("Chloroethane")(C_2H_5Cl + SO_2(g)) uarr + HCl_((g)) uarr`
`underset("Ethanol")(C_2H_5OH) + HCl (g) overset("Pyridine")to underset("Chloroethane")(C_2H_5Cl + H_2O)`
The second reaction is generally carried out in the presence of dehydrating agent such as anhydrous `ZnCl_2`.