artemov
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Filtering Barium Carbonate
Just wondering if barium carbonate ppted from barium nitrite (aq) and sodium carbonate (aq) can be easily gravity filtered with a "medium speed"
filter paper?
The barium carbonate will be dried and kept, while the sodium nitrite (aq) will be used soon.
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teodor
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A few days ago I've made barium carbonate by the reaction of Ba(OH)2 and NaHCO3. I used a hot solution of the salts. BaCO3 deposit was very fine but
it was easily vacuum filtered with 615 paper (the fast one). During the process, the paper was clogged, but with the aspirator vacuum that's was not a
problem, just a bit longer time to wait. I've done 2 washes with hot water and 1 with ethanol. The filtrate was clear, so, that's was not a problem.
During drying, however, I've noticed that the mass becomes very dense, and with the quality of a "filling". I've put it in a vacuum desiccator over
CaCl2/KOH and after 1 day it is still a bit wet.
So, I don't think the filtering (with aspirator vacuum) would be a problem, but I think the size of particles could be also dependent on the solution
temperature.
[Edited on 21-2-2022 by teodor]
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artemov
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Quote: Originally posted by teodor  | A few days ago I've made barium carbonate by the reaction of Ba(OH)2 and NaHCO3. I used a hot solution of the salts. BaCO3 deposit was very fine but
it was easily vacuum filtered with 615 paper (the fast one). During the process, the paper was clogged, but with the aspirator vacuum that's was not a
problem, just a bit longer time to wait. I've done 2 washes with hot water and 1 with ethanol. The filtrate was clear, so, that's was not a problem.
During drying, however, I've noticed that the mass becomes very dense, and with the quality of a "filling". I've put it in a vacuum desiccator over
CaCl2/KOH and after 1 day it is still a bit wet.
So, I don't think the filtering (with aspirator vacuum) would be a problem, but I think the size of particles could be also dependent on the solution
temperature.
[Edited on 21-2-2022 by teodor] |
Thanks teodor ... would you think gravity filtration will be a problem? I dun mind waiting a while for the particles to settle down first before
decantation then filtration, though I am a bit worried about the stability of the sodium nitrite solution ...
Would I get larger particles from a colder solution? I assume the barium carbonate particles would be formed instantaneously, would the temp of the
reactant solutions/product mixture matter?
[Edited on 21-2-2022 by artemov]
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teodor
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I don't know, but in my case, it looks like the mass of precipitated BaCO3 is hard to totally separate from water without a vacuum, the mixture is
clay-like. Also, the ability to clog the filter paper suggests that gravity filtration could be a problem.
I don't know how the temperature will change the particle sizes, it is only my guess that it could play some role.
[Edit]
If you have some organic solvent heavier than water (and not miscible with it) you can try to add it to the mixture. Then the solvent and BaCO3 should
form the bottom layer and you nitrite solution a top layer, so they could be probably easily separated after that.
Also doing the reaction in presence of organic solvent can change the size of particles, but I have no idea in which direction.
[Edited on 21-2-2022 by teodor]
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artemov
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| Quote: Originally posted by teodor | I don't know, but in my case, it looks like the mass of precipitated BaCO3 is hard to totally separate from water without a vacuum, the mixture is
clay-like.
[Edited on 21-2-2022 by teodor] |
Ahhhh thanks ... it's what I (don't) want to hear ...
I have dcm ... I'll see if it's worth doing it this way ... thanks again.
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S.C. Wack
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Maybe. The question is a bit esoteric. No problem when obtained by other means. Boiling for a time wouldn't hurt.
https://www.youtube.com/watch?v=8AHCfZTRGiI
I filtered sulfate today. It was made from the hydroxide. So maybe it's off topic. This will filter in a Buchner without vacuum, average 1 drop/5
seconds. But the modern technique rarely seen in the old lab manuals was used. Glass wool pressed in the neck of a kitchen funnel.
This is mentioned because the first pass of about 3 drops a second gave a cloudy filtrate. Barium sulfate which has not settled any after standing for
several hours is known as "really fucking fine", and further filtration was unnecessary for my purposes, but a second pass at half speed was made
anyways, with fresh wool packed tighter. This removed even the RFF grade. I would find a way.
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macckone
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In my (anecdotal) experience barium salts are easier to filter than calcium salts, but particle size may have a big effect and there are way too many
variables to make a definitive statement. Calcium salts tend to clog filters and be a real pain. Magnesium hydroxide gives it a run for its money
forming that wonderful suspension known as milk of magnesia.
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Fantasma4500
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with such a basic chemical i would have redissolved the whole bunch of HCl and reacted once more with Na2CO3 in hopes of getting a different particle
size, if the reaction was slow and yielded small particle size, i would react it by mixing 2 concentrated solutions
having bulk quantities of HCl is its own type of freedom, infact bulk supply of basic chemicals is rarely regrettable, especially not if you look at
the prices of 1L vs 25
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