Barium Hydroxide

[Sebbass69]

Would it be possible to synthesize Ba(OH)2 from an aqueous solution of sodium hydroxide and barium chloride.

The reaction would look something like:

BaCl2 + 2 NaOH --> Ba(OH)2 + 2 NaCl

Because Ba(OH)2 is not nearly as soluble as the other salts, it would fall out of solution - not all of it, but some of it.

Now, if I was to use something like barium acetate, that wold be far more soluble in water (about 66 grams per 100 ml vs. 37.5 grams per 100 ml) and this would mean I could add more barium ions to less water, and therefore get more barium hydroxide out of the solution (due to less water, and more barium)

So, my reaction would look like:

Ba(CH3COO)2 + 2 NaOH --> Ba(OH)2 + 2 NaCH3COO

Does anyone know if any of this would be possible?

[UC]

Yes, this is a simple metathesis/precipitation reaction.

 

Keep in mind that barium compounds are quite toxic and the hydroxide is very sensitive to reaction with [ce] CO2 [/ce].

[Sebbass69]

thank you for your help -

Yeah, I know that water soluble barium salts are very toxic -

[Sebbass69]

I performed this reaction, and it worked perfectly. However, I don't seem to be able to dry the material I have produced. Normally, I would heat it in a small oven, but the Ba(OH)2 is reactive with carbon dioxide, and therefore would react while drying. My first though was to make a chamber, with a small dish of sodium hydroxide, and a small dish of barium hydroxide to be dried. The Ba(OH)2 would be sealed, and the sodium hydroxide would be open. The NaOH would absorb all the CO2 from the chamber, and after all the CO2 is absorbed, the dish with the barium would be opened, and the evaporated water would be absorbed by the NaOH remaining. If need be, a small heating element could be added above or below the Ba(OH)2 to drive off any water. The only other way I could do this, would be to make a completely sealed oven, and perform the same process with NaOH to remove CO2. Anyone have any thoughts, or simple ways of drying the barium hydroxide?

[hermanntrude]

I'd probably wash it with ethanol of acetone, then put it in a dessicator with a dessicating agent and NaOH

[Sebbass69]

Why acetone / ethanol?

[UC]

I'd probably wash it with ethanol of acetone, then put it in a dessicator with a dessicating agent and NaOH

 

NaOH is a decent dessicant itself. Perhaps a very concentrated solution or paste of NaOH (excruciatingly hard to dry out, so the Ba(OH)2 will dry much faster) would be better to absorb CO2 rapidly and a tray of conc. sulfuric acid to dry the air.

 

Using acetone is asking for condensation products when applied directly to a strong base. I'd shake with a tiny bit of ice cold distilled water so you lose only a small bit of barium hydroxide to saturate the solution and then suction filter through a frit and get it into that dessicator ASAP.

 

If you want to build a setup to dessicate in nonreactive gas, I suggest you invest in a cylinder of nitrogen or argon.