How do you separate #"Ba"^(2+)# from #"Pb"^(2+)# in a mixture?
1 Answer
Dec 9, 2017
Well, the iodide anion precipitates
This is what we expect from solubility rules---iodides, chlorides, and bromides are generally soluble, with lead(II) being one of the few exceptions.
And thus, we can form a procedure from this data to separate a mixture of these two cations.
- Add about 5 mL of solution into a small test tube.
- Add a few droppers of
#"NaI"(aq)# to precipitate#"PbI"_2(s)# in a small test tube. - Centrifuge for about 2 minutes to maximize separation, then let the machine slow down on its own.
- Extract the supernatant (containing mostly
#"Ba"^(2+)# and#"I"^(-)# , and maybe trace dissolved#"Pb"^(2+)# ) into a separate test tube.
Should be mostly separated at that point.
