A student obtains an unknown coltuion that may contain aqueous Ag+ Pb2+ or Hg2+ or any of the combination of the three. the student performs the following procedures and gets the following results.

a) adds HCl and gets a white precipitate
b)decants the supernatant adds h20 to the precipitate and hears it in a water bath the precipitate remains
c) decants the supernatant and adds (CrO4)2- thick yellow precipitate forms
d)the remaining white precipitate is mixed with ammonia and the precipitate turns black
e) the supernatant is decanted and acidified with nitric acid no precipitate forms

1) what ions were present in the unknown
2)write net ionic equations for all reactions that occured

u dont have to do the ans for me just lead me in the right direction