# Reaction of Lead(II) Chloride and Ammonia

While searching how to identify cations in a solution I found that ammonia could be used to distinguish between $$\ce{AgCl}$$ and $$\ce{PbCl2}$$ precipitates after $$\ce{HCl}$$ had been added.

Why does the addition of ammonia cause $$\ce{PbCl2}$$ to dissolve while $$\ce{AgCl}$$ doesn't? (With chemical equations if possible.)

• Are you sure you have this right? I thought the silver compound was the one that dissolves. – Oscar Lanzi Jul 13 at 9:43
• I used to do this lecture demo: add NaCl soln to silver nitrate soln to precipitate AgCl. Then add concentrated ammonia soln to dissolve the AgCl. Then add KBr soln to precipitate AgBr. Then add sodium thiosulfate soln to dissolve the AgBr. Then add KI soln to precipitate AgI. Then add KCN soln to dissolve the AgI. (I skipped the last step in the lecture hall, for safety reasons.) I suggest looking up the various silver complexes than can form. Also, if I remember correctly, there are both silver and lead chloro complexes and HCl was used initially. Hope this helps and +1 to Oscar Lanzi. – Ed V Jul 13 at 14:02
• @Oscar Lanzi is correct ,Silver ion in ammonia solution forms a soluable complex. – Chakravarthy Kalyan Jul 13 at 16:35