[Beatles]

How can I precipitate K-Compounds?

Another question: is there any method to complex K+

[Alberto_Kravina]

How can I precipitate K-Compounds?

there are not so many insoluble Potassium salts, but there are still some: Potassium tetraphenylborate, Potassium perchlorate and potassium hexaniturocobaltate(III). You can precipitate those potassium salts by adding the sodium salt (Sodium tetraphenylborate, sodium perchlorate and sodium hexanitrocobaltate(II)

Another question: is there any method to complex K+

Google "Crown Ether"

[Beatles]

Thank you very much.
Is ther any way to preccipitate sodium sallts?

[Alberto_Kravina]

Thank you very much.
Is ther any way to preccipitate sodium sallts?

There are only 2 insoluble sodium salts: Sodium hexahydroxoantimonate(V) and sodium magnesium uranylacetate. Precipitation with potassium hexahydroxoantimonate and magnesium uranylacetate.

[jdurg]

That's why Uranyl Nitrate is one of the most useful compounds in an analytical lab because not much else can precipitate sodium ions.  The one downside is that uranyl nitrate solution is fairly toxic and mildly radioactive.  

[Alberto_Kravina]

Yo! My lab teacher measured the radioactivity (with a Geiger counter) of the uranyl acetate and it was pretty weak.

[Mitch]

Natural uranium is a "weak" source of radioactivity in general.

[jdurg]

Natural uranium is a "weak" source of radioactivity in general.

Yup.  I was able to find that out firsthand.  Took my uranium and set it next to some undeveloped film.  I figured the film would be developed by the radiation emitted within a few hours.  It actually took about a day and a half for the film to show significant exposure.  So the radiation emitted from uranium is fairly weak.  In addition, it has such a long half-life that it doesn't emit a lot of radiation either.  My uranium, which has a fairly large surface area, is inside a glass vial filled with mineral oil.  The glass is about 3.5 mm thick, and the two layers of lead shielding lining the box the vial is in are about 2mm thick each.  All of that is plenty enough to stop all radiation from the uranium.  (I.E. I can't detect anything.  Gamma rays or x-rays.)

[pantone159]

Can you detect betas?  I have a counter with a mica window that easily lets betas and even alphas in.

I get pretty different results checking a 5g U sample, which is sealed under Ar in a glass vial.
Background is 31 +/- 4 counts per minute, when I place the vial with the U next to the geiger counter, I get 12360 +/- 80 counts per minute.  About 400 times as high.

I believe that Geiger counters are far more sensitive to betas than gammas (detecting c. 100% vs 1 or 2% of incident particles).  I suspect that the radiation from my U is mostly betas from Pa-234 decay (no alphas get through the vial), vs background which is entirely gammas, so the relative increase in radiation is not nearly as large, but it still seems like a dramatic difference.

[jdurg]

Can you detect betas?  I have a counter with a mica window that easily lets betas and even alphas in.

I get pretty different results checking a 5g U sample, which is sealed under Ar in a glass vial.
Background is 31 +/- 4 counts per minute, when I place the vial with the U next to the geiger counter, I get 12360 +/- 80 counts per minute.  About 400 times as high.

I believe that Geiger counters are far more sensitive to betas than gammas (detecting c. 100% vs 1 or 2% of incident particles).  I suspect that the radiation from my U is mostly betas from Pa-234 decay (no alphas get through the vial), vs background which is entirely gammas, so the relative increase in radiation is not nearly as large, but it still seems like a dramatic difference.

Hehe.  Go and take your geiger counter and put it next to a similar sized piece of uranium ore.  The numbers would be MUCH higher than the pure Uranium.    The lower cost geiger counters are much more sensitive to alpha and beta particles due to how they interact with other things.  They work on a basis where the charged alpha/beta particles alter the conductivity of a gas inside the detection chamber.  Gamma rays are not charged particles and only create a charged particle if they interact with something and kick off an electron.  As a result, unless you have a detector tuned to detect the gamma rays you'll have a tough time finding them.  (I'm fortuneate in that I have contact with someone who works at a nuclear power plant so he is able to let me use some pretty high tech detection equipment every now and then).

[pantone159]

Go and take your geiger counter and put it next to a similar sized piece of uranium ore.  The numbers would be MUCH higher than the pure Uranium.  

Yeah, I have a nice piece of U ore.  Actually, it is a lot bigger than 5g, so it makes quite a show.

Someday, I hope to be able to get a (fairly) low cost, good resolution, gamma ray spectrometer.  That would be lots of fun to mess with.  AFAIK, the choices are still low-res NaI detectors, and liquid N2 cooled, better resolution semiconductor detectors, neither of which meet my budget requirements.