Making Lead Tetraoxide

[10fingers]

I got this formula for lead tetraoxide from Wouter's page and I've tried it twice and it doesn't work. It goes like this;
Prepare a concentrated solution of 300 gms sodium hydroxide in water. When all has dissolved allow to cool to room temperature.
Dissolve 50 gms of lead nitrate in 200 ml water.
Slowly add sodim hydroxide solution to lead nitrate solution while stirring continously. A white precipitate will form which will slowly turn orange when all sodium hydroxide solution is added.
Filter out lead tetraoxide and wash several times with hot water.
Okay, when I do this I get the white precipitate, but after about half the sodium hydroxide is added a greenish gray precipitate forms. No orange at all.
This precipitate looks a little more like lead monoxide to me.

[megalomania]

I believe this procedure might require the precipitation to be conducted in ice cold water or else the tetroxide decomposes to the monoxide. Lead tetroxide is reddish in color, so if you don't get that orange solution you are certainly not getting lead tetroxide.

There is a procedure in the Handbook of Preparative Inorganic Chemistry IIRC.

[10fingers]

Ok, Thanks. I will give it a try as soon as I make some more lead nitrate. In the meantime, I have a lot of lead monoxide that I am going to try to convert to the tetraoxide by heating it to between 300 and 500 C.

[10fingers]

I took some of my lead monoxide and heated it for a couple of hours at 400 C. It did not change color so I added some KNO3. I kept heating it and it changed color from a pale yellow to a light orange, about the color of yams. I washed it several times to remove all the KNO2 and KNO3. The color remained orangish, I think I may have some lead tetraoxide.
Now I need to know how to separate it from any lead monoxide that may still be in it and to test it to see if it is lead tetraoxide. I can not find much info on what solvents will work, at least not any common ones. They are both insoluble in water.
I tried a little bit of it in a high temp thermite mix with silicon and it did burn but I think lead monoxide will also act as an oxidizer and burn. At one I time I had some pure lead tetraoxide and I tried it in this same thermite mix and it seemed to burn a little better and hotter.