Hi chemistry enthusiasts! I am working on my scholarship exam practice. I believe this exam assumes high school + first year university knowledge although the standard may be varied across the world. And I'm not quite sure what I did wrong. Could you please have a look?
There is an aqueous solution containing Cu2+ and Pb2+ ions. The most suitable reagent to precipitate one of the two ions from the solution is (1) nitric acid (2) sodium carbonate (3) sulfuric acid (4) hydrogen sulfide
I picked answer (4) hydrogen sulfide because I think that it will react with copper (II) ions and will precipitate out. However, the correct answer is (3) sulfuric acid. How is this answer correct and what did I do wrong for hydrogen sulfide. Your advice will be much appreciated!