IF AFTER PRECIPITATION OF THE GROUP I CATIONS AS CHLORIDES BY THE REACTION WITH HCL NEARLY ALL OF THE PRECIPITATE DISSOLVES IN THE HOT WATER. WHAT ION IS MOST PROBABLY PRESENT AND WHICH IONS ARE MOST PROBABLY ABSENT?

Answer 1

Please, not all caps.
The ppt probably is PbCl2 so Pb^2+ is present and Ag^+ and Hg2^2+ probably are absent.