write the name or formula for a reagent that will dissolve PbCl2 but not Hg2Cl2 and AgCl?
hot water.
To identify a reagent that can dissolve PbCl2 but not Hg2Cl2 and AgCl, we need to consider the solubility rules for these compounds. Here's how you can determine the answer:
1. Begin by understanding the solubility rules for common ionic compounds. These rules outline the general solubility patterns for different types of compounds. In this case, we need to focus on the solubility of lead chloride (PbCl2), mercury(I) chloride (Hg2Cl2), and silver chloride (AgCl). The solubility rules state that:
- Lead chloride (PbCl2) is soluble in water.
- Mercury(I) chloride (Hg2Cl2) is insoluble in water.
- Silver chloride (AgCl) is insoluble in water.
2. Based on these solubility rules, we need a reagent that can selectively dissolve PbCl2 while leaving Hg2Cl2 and AgCl untouched.
3. A suitable reagent for this purpose is hydrochloric acid (HCl). When added to the mixture of PbCl2, Hg2Cl2, and AgCl, hydrochloric acid will dissolve PbCl2 but not Hg2Cl2 or AgCl.
The reaction between hydrochloric acid and lead chloride (PbCl2) can be represented by the following equation:
PbCl2 + 2HCl → PbCl2·2H2O
In this reaction, PbCl2 forms a complex with water, resulting in its dissolution.
So, the reagent that can dissolve PbCl2 but not Hg2Cl2 and AgCl is hydrochloric acid (HCl).