Naked Science Forum
Non Life Sciences => Chemistry => Topic started by: bigblock on 22/09/2012 04:13:35
-
I was looking for some tin and buddy told me about lead free/tin fishing weights. I went and bought a pack. When I tried to dissolve in HCL I ran into nothing but problems. I called the manufacture and asked if this was pure tin and they told me yes. Some tin fishing weights advertise bismuth in the mix but this company does not. Their claim is tin. What simple experiment can I do to to see in there is bismuth mixed in the tin?
-
Interesting, bigblock. What specifically do you mean by "ran into problems"? Can you describe your observations?
Look up "tin pest" or "tin allotropic modification" on the web. You will be able to tell if you have (reasonably) pure tin or not if you put it in the freezer for a year or so!
Did your material refuse to dissolve in HCl? Or did it dissolve very slowly? Using chlorine bleach or a mixture of chlorine bleach and HCl (beware chlorine fumes) or peroxide and HCl will almost certainly help dissolve your metal. Separating bismuth and tin is more easily done with aqueous solutions of the three chlorides {tin(II) chloride, tin(IV) chloride, and bismuth(III) chloride}than with the metals themselves.
-
The problem was the tin did not dissolve in Muriatic acid. I placed a gram piece in a test tube with 15 mL of muriatic after I flattened it paper thin. When I was appling heat I noticed the metal wasn't reacting very much. After several minutes the acid evaporated leaving the flattened metal almost untouched. I tried a second time but added more muriatic as it evaporated and still the the same results. My reason for doing this was to make stannous chloride solution but I guess that will have to wait until I can find better tin. Do you think the reason it didn't dissolve was because I was using muriatic instead of pure HCL?
-
I do not know the concentration of the stuff you buy as muriatic acid. It is not a name that we have in this country, though I know that it is the same as hydrochloric. The best references that I have suggest that to dissolve tin at any reasonable rate, the hydrochloric acid has to be hot and concentrated.
The other thing that the references seem to say is that the reaction of tin with hydrochloric acid produces tin(IV) chloride rather than tin(II) chloride.