Question

would acetic acid behave like a strong acid when dissociate in liguid ammonia ?

Answer 1

Quite possibly. Any proton-transfer reaction is all about the competition between two bases for an H+. When HOAc dissolves in water, the OAc- anion and H2O compete for the H+. Since OAc- is the better base, it wins, and the HOAc remains largely undissociated. By contrast when HCl dissolves, the Cl- is a much weaker base than H2O, so the H2O wins, and you get lonely Cl- plus victorious H3O+.

But NH3 is a significantly stronger base than H2O, so in the competition between OAc- and NH3 for the H+, it's possible NH3 wins, and the HOAc will fully dissociate the way HCl does in aqueous solution.

But I wouldn't know if it actually turns out that way without looking up the numbers, and I might as well leave that bit for you.