Question

The function of `ZnCl_(2)` in Lucas test for alcohols is
A. To act as acid catalyst and react with HCl to form `H_(2)ZnCl_(4)`
B. To act as base catalyst and react with NaOH to form `Na_(2)Zn(OH)_(4)`
C. To act as amphoteric catalyst
D. To act as neutral catalyst

Answer 1

Correct Answer - A
Lucas test : In the presence of anhydrous `ZnCl_(2), ` alcohol reacts with conc. HCl to produce alkyl chloride.
`ROH + HCl overset(ZnCl_(2))to RCl + H_(2)O`
Mechanism of Lucas test
`2HCl + ZnCl_(2) to H_(2)ZnCl_(4)`
`ROH +H_(2)ZnCl_(4) to RCl + ZnCl_(2) + H_(2)O + HCl`
`uloverline(ROH+HCl overset(ZnCl_(2)) toRCl + H_(2)O)`