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?
Please, not all caps.
The ppt probably is PbCl2 so Pb^2+ is present and Ag^+ and Hg2^2+ probably are absent.
To determine which ion is most probably present and which ions are most probably absent after the precipitation of group I cations as chlorides through the reaction with HCl, we need to understand the solubility of different chloride salts in water.
Group I cations include Ag+, Pb2+, and Hg2+.
The solubility rules for chloride salts are as follows:
1. Most chloride salts are soluble in water, except for those of silver (Ag+), lead (Pb2+), and mercury(I) (Hg2+). These three ions form insoluble chlorides that precipitate when reacted with chloride ions.
Based on the information given, if nearly all of the precipitate dissolves in hot water, it suggests that one of the group I cations is not present as an insoluble chloride. Therefore, the ion most probably present is:
- Hg2+ (mercury(I))
Since the other two ions, Ag+ (silver) and Pb2+ (lead), form insoluble chlorides, they are most probably absent.
So, to summarize:
- The ion most probably present is Hg2+ (mercury(I)).
- The ions most probably absent are Ag+ (silver) and Pb2+ (lead).