Sciencemadness Discussion Board

Pyrophoric lead and tin

jimmyboy - 1-4-2007 at 21:30

Would lead chloride be interchangeable with lead nitrate I wonder? I want to precipitate lead tartrate from commonplace items.. shortage of nitric acid on the store shelves these days :D

Edit by Chemoleo: Title.

[Edited on 4-4-2007 by chemoleo]

12AX7 - 1-4-2007 at 21:39

For.....what......?!

jimmyboy - 1-4-2007 at 21:51

pyrophoric lead

Maya - 2-4-2007 at 03:57

No it would not

jimmyboy - 2-4-2007 at 11:56

actually i think the acetate would work since it is more soluble than lead nitrate - easy to get as well

I am experimenting with Homburg's pyrophorus as well (alum + sugar) if anyone has messed with it - tell me

here is a cool pic of pyrophoric iron

http://mse.mcmaster.ca/faculty/coley/myimages/coley_pyro.jpg

[Edited on 2-4-2007 by jimmyboy]

woelen - 2-4-2007 at 14:09

Lead tatrate seems to work. Read the following link, it mentions lead tartrate and tin oxalate as sources for pyrophoric lead and tin.

http://www.chemsoc.org/pdf/LearnNet/nc/classicdem_nc9.pdf

The experiment with pyrophoric iron is very neat indeed. I have some FeC2O4.2H2O and it works like a charm. Also funny is the really weird free-flowing properties of the dark grey/black powder, which is produced, when CO2 is emitted. The powder is floating on a blanket of CO2 between the bottom of the test tube and itself. Really nice to see this.

garryb - 3-4-2007 at 02:35

woelen, I liked the extract from Classical Chemical demonstrations so much I wanted to see the whole series. I have found it available from the Royal Society of Chemistry, but at 27.50 GBP I wanted to get opinions of others before investing so much. Would you (or others) recommend the investment? Are any other sample pages visible on the internet to help me make up my mind? Many thanks, Garry.

Levi - 3-4-2007 at 02:58

Does Homberg's mix use hydrated alum or is the fully dehydrated form required to make the reaction work? The site I found seems to suggest that the carbon (or sugar) is reducing the sulfate in the alum to SO<sub>2</sub> but if this is the primary mechanism for the reaction why should it ignite on contact with air? Additionally, all the oxygen required to sustain the reaction should be contained in the alum so once ignited the mix should continue to burn even in an inert atmosphere.

2Al(NH<sub>4</sub>;)(SO<sub>4</sub>;)<sub>2</sub> + 4C --> 4CO<sub>2</sub> + 2SO<sub>2</sub> + 2NH<sub>3</sub> + Al<sub>2</sub>O<sub>3</sub> + H<sub>2</sub>O

Have I correctly predicted the products or is the SO<sub>2</sub> being reduced all the way to S<sub>8</sub>?

[Edited on 3-4-2007 by Levi]

jimmyboy - 3-4-2007 at 11:24

I dont think the alum has anything to do with the reaction besides making the carbon very finely separated and drying it -- the carbon becomes pyrophoric from the surface area exposed to the oxygen - I am still looking for more details though - the literature I have found on Homburg's is sketchy at best..

from what i understand at high temperatures, alum decomposes into K2SO4, Al2(SO4) and H2O

woelen - 3-4-2007 at 12:41

Quote:
Originally posted by garryb
woelen, I liked the extract from Classical Chemical demonstrations so much I wanted to see the whole series. I have found it available from the Royal Society of Chemistry, but at 27.50 GBP I wanted to get opinions of others before investing so much. Would you (or others) recommend the investment? Are any other sample pages visible on the internet to help me make up my mind? Many thanks, Garry.

Yes, I like the experiments, I have seen on the website. Here are more of these experiments:

http://www.chemsoc.org/pdf/LearnNet/nc/

I think that the complete series for GBP 27.50 is good value for money, but of course, it indeed is quite a lot of money and it depends on the contents of your wallet whether you want to spend that money, or not. It also depends on your available chemicals. A set of experimental descriptions can be very nice, but if you cannot do any of them, due to lack of chemicals, then it only is frustrating. I personally, however, spent quite a lot of money on books (more than EUR 300 over the last few years), because I like it. I like sitting comfortably in the couch, reading an interesting book. Its worth the money for me and I like it much more than sitting behind the computer screen, reading the things from a website ;).

chemoleo - 3-4-2007 at 16:27

Here's more information
https://sciencemadness.org/talk/viewthread.php?tid=335&p...

The_Davster - 3-4-2007 at 16:50

Quote:
Originally posted by woelen
Also funny is the really weird free-flowing properties of the dark grey/black powder, which is produced, when CO2 is emitted. The powder is floating on a blanket of CO2 between the bottom of the test tube and itself. Really nice to see this.


Really? Wow! When I made pyrophoric iron from homemade iron oxalate I had a rather difficult time getting it out of the tube to spontaneously combust. Got pictures? Metal floating on CO2 has to be fascinating to see.

woelen - 4-4-2007 at 02:35

I used commercial lab grade ferrous oxalate dihydrate for this experiment, which I purchased from an eBay seller. I once tried to make this myself, but it is very difficult to make a suitably pure sample. I used potassium oxalate and Mohr's salt for making ferrous oxalate, but the product was very hard to isolate (hardly settled) and I think it contained quite a lot of potassium and sulfate ions. With the commercial stuff, I however, had really nice results.

I plan to make a webpage in the experiments section of my website on this subject, with a video of the very fluffy powder, while emitting CO2. Making a nice closeup-video of this is not easy though, I am not easily made happy with this kind of things :D.

garryb - 5-4-2007 at 09:02

Many thanks woelen for your assistance and comments. I have a good selection of chemicals and would be able to do most of the things you have posted, so I will invest in the series. Like you I also like to read (and probably spend more time reading than doing chemistry!), so the set will be double value for me. Thanks again for helping me to decide, Garry.