Biochem
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Lead Thiocyanate synthesis again....
Hey I have a question on lead thiocyanate synthesis similarly like the one posted earlier. I'm currently doing a research experiment at a
university where I am given control of what I buy etc. My beginning is substance is solder and I am to somehow synthesize two compounds: Pb(SCN)2 -
Lead thiocyanate and K3PbI3 which I believe is a type and should be KPbI3 instead. Does anyone have any idea of what procedures I should go through to
get these two compounds as my end product or what references to look up? Thanks alot.
[Edited on 7-4-2004 by Biochem]
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The_Davster
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What type of chems can you use, other than the solder? Do you have to create the thiocyanate ion? If you have access to anything the lead thiocyanate
synth could be something like this.
Pb(in solder) + HNO3---> Pb(NO3)2 +NO2
2NaSCN + Pb(NO3)2-->2NaNO3 + Pb(SCN)2 the lead thiocyanate would precipitate out. I dont have any ideas about the second one though.
[Edited on 7-4-2004 by rogue chemist]
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BromicAcid
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You should note that new solder does not have lead in it to my knowledge. It is mostly silver/tin solder on the market now adays.
[Edited on 4/7/2004 by BromicAcid]
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The_Davster
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Bromic Acid: Thats weird, last time that I saw solder(about 1 week ago) there was 2 types; one said "danger: contains lead, a chemical known
to...", and the other said "lead-free solder". I guess it depends where you look, I saw this at either Revy/Rona or at home depot.
YAY...100th post...I'm a hazard to others now  
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Mr. Wizard
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You are right about the new solder not containing lead, but the stuff you buy at the hardware store will be tin/antimony Sn95%/Sb5% You can buy some
specialty 'silver solders' that may contain a very small percentage of Ag. Your best bet for Lead (Pb) would be to visit a tire store,
with a 6 pack of cola or beer and a bag of potato chips and ask for a bucket of lead wheel weights. Expect to be turned down, but be polite and ask
for a few handfuls. Bring your own bucket or heavy bag. The ones with the steel clips on them contain a few percent antimony and who knows what else,
but they are mostly lead. The pieces of thin lead in the bucket they pull off of alloy wheels, is almost pure lead. This is the stuff with the double
sided tape on it. Another good spot to gather metal is the back dumpster of an air conditioning repair store. They often throw away electrical
'contactors', which are nothing but heavy duty relays handling the current to the large compressors. These contactors contain buttons of
pure silver. Break up the plastic part of the unit with pliers or a hammer, wearing eye protection. You will see the silver on the end of the
moveable part of the relay, and on the stationary parts it hits. They are often stained black. The buttons are riveted, soldered , or welded to a
brass or copper arm. Even very small relays often contain surprising amounts of this increasingly expensive metal. It is over $8 a troy oz today.
Some low current cheap relays do not contain silver but have some other alloy on them, perhaps Tungsten. Has anyone else been dumpster diving for
these little gems? BTW, keep your eyes peeled for those old Mercury filled thermostats too.
While you are at the tire store, look to see if they turn brake drums and disks. If they have a lathe, the floor under it will be covered with cast
iron turnings that look like black sawdust. You never can tell when you might need some iron filings.
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Biochem
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Thanks all for the help. I believe I can use almost any chemical you would find in a chemistry lab at a university. I'm still unsure about the
KPbI3 if anyone else has any more suggestions it would be much appreciated
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The_Davster
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I found a few sites that mention the elusive KPbI3. BTW the name of the compound is potassium lead triiodide. If you google the formula you get a
lot of non english sites-I cannot tell what language it is in. Heres a sample of the language-anyone recognise it?
Межконфессиональный
Христианский ...
http://www.chempage.de/lexi/kaliumiodid.htm - in german, unfortunatly my german is not advanced enough to translate this. KPbI3 is mentioned
last paragraph.
http://journals.iucr.org/b/issues/1980/04/00/a18729/a18729.p... -need to subscrbe to viev any info
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darkflame89
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Let me guess is the language Russian??
Ignis ubique latet, naturam amplectitur omnem.
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Theoretic
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Yes it IS Russian!
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