Sciencemadness Discussion Board

Lead compound

nguyenvannam2904 - 11-8-2020 at 01:19

Can PbCl2 react with HNO3 to form Pb(NO3)2 ?
If yes, what product can be formed beside Pb(NO3)2?

woelen - 11-8-2020 at 01:41

Using PbCl2 for making Pb(NO3)2 is not impossible, but the reaction and workup is not easy.

PbCl2 is only very sparingly soluble in aqueous solution. In hot concentrated HNO3, this slowly reacts to form Pb(NO3)2, ONCl and Cl2. The Pb(NO3)2 also does not dissolve easily, especially if the acid is more concentrated. On the other hand, if the acid is not that concentrated, then the redox reaction in which the chloride is converted to ONCl and Cl2 hardly occurs. I expect that you will have a hard time getting Pb(NO3)2 in decent amounts and of decent purity with HNO3.

If you want Pb(NO3)2, then dissolve lead metal in nitric acid. That reaction works much better. On cooling down, crystals of Pb(NO3)2 separate from the acid. These crystals still contain quite some trapped acid, but when you dissolve them in hot water and allow the solid to crystallize again (let the water evaporate in a dish over a few days), then your product is quite pure.

RogueRose - 11-8-2020 at 02:51

Do you already have the PbCl2?

I think I got some kind of hydroxide or hydroxide/carbonate when I was trying to neutralize a solution of lead chloride and I'm guessing I would have used sodium carbonate, possibly with a little NaOH in it as well. IIRC, I do remember it being a difficult product to work with but I can't remember if it was making it or neutralizing it when I wanted to dispose of it.

If you already have the chloride and want the nitrate, then maybe you can make the carbonate/hydroxide and then add the nitric acid.?

IDK where you got the lead, but I've had some very trying times working with lead from batteries and even after conversion to a salt (acetate in this case), it didn't turn back to a very usable form of lead when I either decomposed it or did a displacement reaction. The lead remained in a very strange form that seemed resistant to melting in the metal form w/o oxidizing at an incredibly high rate.

nguyenvannam2904 - 11-8-2020 at 05:36

I use soldier wire which has about 37% Lead and 63% tin. Then I put the soldier wire in the solution of 30% HCl + 30% H2O2 in equavalent amount. The reaction happened in about 2 hours. Then in the reaction flask, I see a bunch of solid white stuff. I boil of the flask to recrystalize PbCl2 then filtered the solution and collected PbCl2. This method give the high yield of PbCl2 :D

nguyenvannam2904 - 11-8-2020 at 05:46

I tried to dissolve the soldier wire into concentrated HNO3 but I don't have any idea to seperate Sn(NO3)2 and Pb(NO3)2 :(

AgCollector - 11-8-2020 at 08:18

Quote: Originally posted by nguyenvannam2904  
I tried to dissolve the soldier wire into concentrated HNO3 but I don't have any idea to seperate Sn(NO3)2 and Pb(NO3)2 :(


I've never done this personally but from what I've read it should form an insoluble tin(IV) compound "metastannic acid", and the lead(II) nitrate stays in solution.

Bedlasky - 11-8-2020 at 11:04

Quote: Originally posted by AgCollector  
Quote: Originally posted by nguyenvannam2904  
I tried to dissolve the soldier wire into concentrated HNO3 but I don't have any idea to seperate Sn(NO3)2 and Pb(NO3)2 :(


I've never done this personally but from what I've read it should form an insoluble tin(IV) compound "metastannic acid", and the lead(II) nitrate stays in solution.


I once dissolved some tin/lead solder in analytical labs. Tin precipitated out as hydrous SnO2 and lead remained in solution.

Btw. tin(IV) nitrate does exist, but it's quite unstable and hydrolyze in to hydrous SnO2:

http://tin.atomistry.com/stannic_nitrate.html