Sodium Sulfate Creation for Drying Agent

[Gone-and-Back]

Now sure if this is the best place to post this, but I felt it was not "advanced" so no need to place it into the advanced chemistry forum. Also, if this borders on synth talk I apologize, but I believe this should be ok to talk about as it's something anyone can do with easily obtainable materials.

A friend of mine came up with a way to create anhydrous sodium sulfate for desiccant purposes. It's very simple and requires very little materials. You will need;
Lye
Water
Magnesium Sulfate (Epsom salts)
Filtering equipment

Basically you take an aqueous sodium hydroxide solution, and to this you add your magnesium sulfate. There should be a reaction that occurs that will form both magnesium hydroxide, and sodium sulfate. The magnesium hydroxide will be insoluble and crash out almost instantly. Filter this out and save the aqueous sodium sulfate. Now bring this solution down to below 20C and all the sodium sulfate should rapidly crystallize. Filter this out and you have sodium sulfate.

This can be used the same was as anhydrous magnesium sulfate, but does not form by products with solvents like acetone like the magnesium sulfate does ( at least this is what I am told).

I'd love to hear your thoughts on this process

 

[Auxin]

Safer and cheaper way that will give cleaner product:

Bake baking soda in the oven or obtain washing soda
Dissolve in water, also dissolve a molar equivalent of epsom salts in water
Mix the two
Let settle, decant, and evaporate the solution to yield sodium sulfate

 

[Gone-and-Back]

That seems like a much safer way. I'll pass this along to him. Thanks

 

[downwardsfromzero]

First method sets me wondering about the possible merits of magnesium hydroxide as a base. Use similar to calcium hydroxide in a limetek? Hmmm...

 

[Gone-and-Back]

I'm no chemist, so I do not know what magnesium hydroxide could be used for. Because of the hydroxide though I imagine it would be able to be used as a base, I just don't know how effectively or safely.

Maybe someone will try it or someone with more chemistry knowledge can chime in.

 

[downwardsfromzero]

I'll mention this to my ex-neighbour's cousin's friend whose highly trained Russian steppe hamster may be able to come up with something. Mg(OH)2 is quite a strong base, but even less soluble than Ca(OH)2. It would likely work for basifying a vinegar tea of some kind, possibly Mg(OH)2 would work as a paste in one of the limeteks.

wiki for sodium sulfate

The hydrate of sodium sulfate is known as Glauber's Salt

Sodium sulfate has unusual solubility characteristics in water.[7] Its solubility in water rises more than tenfold between 0 °C to 32.384 °C, where it reaches a maximum of 49.7 g/L. At this point the solubility curve changes slope, and the solubility becomes almost independent of temperature.

Other double salts include 3Na2SO4·CaSO4, 3Na2SO4·MgSO4 (vanthoffite) [...]

In the laboratory it can also be synthesized from the reaction between sodium bicarbonate and magnesium sulfate.

2NaHCO3 + MgSO4 → Na2SO4 + Mg(OH)2 + 2CO2

So no need even to roast your bicarb? Although the chemistry here seems to me rather questionable.

 

[Rabbit]

Magnesium sulfate itself is a very good desiccant. The stuff you buy at the store though is hydrated. You must heat it for a while to make it anhydrous.

 

[downwardsfromzero]

Magnesium sulfate itself is a very good desiccant. The stuff you buy at the store though is hydrated. You must heat it for a while to make it anhydrous.

Magnesium sulphate is a Lewis acid which can cause undesirable by-products to form in acetone drying. Sodium sulfate does not do this.

 

[pitubo]

Pool pH up Na2CO3 plus Pool pH down NaHSO4 also makes Na2SO4.

The places that sell these products usually also sell pH indicator kits, which are useful to check if the neutralization is complete (pH should be near 7).

Obviously you need to check that the pH up and pH down are these exact chemicals. Sometimes pH down is eg. HCl and then the result would not be the same.

 

[FLeP]

I've used magnesium sulfate to dry acetone for salting out mescaline recently. Anyone care to inform me what I've got in my mesc fumarates, how harmful it is, and how I can remove it?

Thanks

 

[downwardsfromzero]

I've used magnesium sulfate to dry acetone for salting out mescaline recently. Anyone care to inform me what I've got in my mesc fumarates, how harmful it is, and how I can remove it?

Thanks

TBH, I've used magnesium sulfate to dry acetone as well. You'll probably be just fine. If you were using the acetone for chromatography or mass spec, there's more of a chance that the MgSO4 could screw things up a bit.

The main by-products are diacetone alcohol, mesityl oxide and isophorone. Water is also a by-product, so the acetone might not get as dry as it could do with a different drying agent. Calcium sulfate is recommended for drying acetone.

 

[pitubo]

I've used magnesium sulfate to dry acetone for salting out mescaline recently. Anyone care to inform me what I've got in my mesc fumarates, how harmful it is, and how I can remove it?

TBH, I've used magnesium sulfate to dry acetone as well. You'll probably be just fine.

Me too. It's not a big problem unless you leave the magnesium sulfate in the acetone excessively long, like months. It should have done most of the drying after an hour at most, so that should be fine.

The main by-products are diacetone alcohol, mesityl oxide and isophorone.

These are all reasonably volatile. Combined with very low quantities expected to be in your acetone as a result of drying agent catalyzed condensations and then only fractions of that eventually sticking to your fumarates leaves little to worry about overall. And these substances are not terribly toxic either, especially not in the minute quantities we're talking about.

In general, I'd be more concerned with the purity of consumer grade acetone as bought from the store than the impurities caused by drying it. OTC acetone is not exactly suited for analytical purposes...

 

[FLeP]

Thanks guys, I'll be looking into calcium sulfate and sodium sulfate.

 

[downwardsfromzero]

Here's a simple method of preparing sodium sulphate crystals for us as a dessicant, no hazardous materials involved! I'm not sure I've seen it posted anywhere on the Nexus yet. It's very simple and uses readily available materials, so here it is:

"Sodium sulphate, Glauber's salt, is obtained by double decomposition between NaCl and MgSO4. Glauber's salt is easily soluble at moderate temperatures, so the mixed solution is cooled to -3 C, when it is deposited and the MgCl2 remains in solution."

2NaCl + MgSO4.7H2O -> Na2SO4.10H20 + MgCl2

e.g. 77 g of table salt will react in c.300 mL aqueous solution with 246 g of Epsom salts to deposit upon cooling 300 or so grams of Glauber's salt. (Theoretical yield of 322 g is not obtained as some remains in solution.)

The sodium sulphate crystals will of course require baking before use as a dessicant. 100 g of the hydrated sulphate should yield about 44 g of the anhydrous salt.