Why does water not interfere with HCl/ZnCl2 conversion of tertiary alcohols?

[Clari]

In the substitution of ROH to RX, dry HCl and anhydrous ZnCl2 catalysts are used for primary and secondary alkanol. Why it is fine to use concentrated HCl and ZnCl2 for tertiary alkanol, that is to say, with small amounts of water present?

 

[GCT]

Think about the mechanism of the reaction, and the trends in the stability of the intermediate

 

[Clari]

so because the carbocation intermediate of tertiary ROH is more stable, so the presence of a little amount of water does not affect the reaction much. Am I right?

 

[GCT]

You're doing the lucas test experiment right? From what I remember, you're supposed to add concentration acid to all solutions, you might want to ascertain whether your manual indicates otherwise.