Sciencemadness Discussion Board - Epsom Salts

Epsom Salts

TheDrowner - 15-1-2007 at 04:06

Is it possible to make an 'effective' smoke bomb, that produces smoke approximately 60 times its volume with magnesium sulphate ( epsom salts ).

If it is, could you explain how???

TheDrowner

[Edited on 15-1-2007 by TheDrowner]

YT2095 - 15-1-2007 at 06:11

I`ve never heard of that one before? are you sure it`s not out of one of these Crapbooks?

Ammonium Chloride is Much better.

woelen - 15-1-2007 at 11:11

MgSO4 can make a smoke bomb. Crunch it to a VERY fine powder and throw it in the air. Instant smoke!

guy - 15-1-2007 at 12:22

LOL!
No offense, but try to learn a little bit about chemistry first.

Chemist514 - 20-1-2007 at 10:27

Quote:

Originally posted by TheDrowner
Is it possible to make an 'effective' smoke bomb, that produces smoke approximately 60 times its volume with magnesium sulphate ( epsom salts ).

If it is, could you explain how???

TheDrowner

[Edited on 15-1-2007 by TheDrowner]

I have really only seen this used in the lab as a dessicant, no students ever "borrow" it, that tells me that its prolly a reagent interesting to people interested in actual chemistry...
I sense though that sice you are saying things like 60 times its volume etc that someone told you it can. I suspect they were lying. but maybe somebdy here with some history of being knowledgable could say for sure.
all the best.

P.S : I recommend not using epsom salts to dry organics.. prolly too low grade. but then again, i know very little.

Ozone - 20-1-2007 at 10:38

Epsom salt is the heptahydrated form. For drying, anhydrous MgSO4 is required.

It dries organics very well, for example, a sample of activated sewage-sludge (70-90% water) can be rendered completely dry by grinding with MgSO4 (dry enough to extract w/DCM and get 90-105% recovery of surrogate, say, decachlorobiphenyl). The heat of hydration is significant.

It also works well for drying out your extract when that inevitable small amount of water gets through your sep funnel. Just dump in a little, swirl, settle and decant (although, I prefer Na2SO4 for this purpose as the grains are larger, and thus more difficult to acidentally "decant".

You will not make smoke bombs from this (NH4Cl will do it-well). As for stink bombs--epsom salt is a pretty good laxative.

Funny Woelen

!

Please search the site,

O3

Chemist514 - 20-1-2007 at 10:46

Quote:

Originally posted by Ozone
Epsom salt is the heptahydrated form. For drying, anhydrous MgSO4 is required.

It dries organics very well, for example, a sample of activated sewage-sludge (70-90% water) can be rendered completely dry by grinding with MgSO4 (dry enough to extract w/DCM and get 90-105% recovery of surrogate, say, decachlorobiphenyl). The heat of hydration is significant.

It also works well for drying out your extract when that inevitable small amount of water gets through your sep funnel. Just dump in a little, swirl, settle and decant (although, I prefer Na2SO4 for this purpose as the grains are larger, and thus more difficult to acidentally "decant".

You will not make smoke bombs from this (NH4Cl will do it-well). As for stink bombs--epsom salt is a pretty good laxative.

Funny Woelen

!

Please search the site,

O3

Hmmnn... would one be able to dry regular epsom salts so that it may be used? much cheaper buying drugstore epsom salts then ACS grade for me!
I did purchase some anhydrous sodium sulfate, but 500 grams only and it was very expensive, this soulds like something to note for the future as oposed to spending hundreds on 2 kilos of magnesium sulfate (anhydrous..)
(the grad students go through LOTS of both of these chemicals.. so i had them on my list to get)
The very best to you.

pantone159 - 20-1-2007 at 11:24

I make my drying agent from MgSO4-7H2O, I put it in the oven for 2 hours at (nominally) 525 F (275 C). [Sorry for the wierd units but that is how my oven is labeled

]

This actually seems to only dehydrate it to the monohydrate, but this is a fine powder as expected and it seems to work.

YT2095 - 22-1-2007 at 09:54

Not really, no.

what is the Chemical?

Baphomet - 22-1-2007 at 15:37

baleeted

[Edited on 22-1-2007 by Baphomet]

[Edit: no recipies please!

]

[Edited on 22-1-2007 by Ramiel]

Levi - 26-1-2007 at 01:48

@ Chemist514 Epsom salt (MgSO4 * 7H2O) is dirt cheap as is Washing soda (Na2CO3). To avoid paying more than you should for Sodium Sulfate you could probably make your own by dissolving epsom salt and washing soda.

MgSO4(aq) + Na2CO3(aq) --> Na2SO4(aq) + MgCO3(s)

If i'm right, the magnesium carbonate will precipitate leaving you with a Sodium sulfate solution which can then be decanted and dried by heating. Anyone know for certain if this method will work?

[Edited on 26-1-2007 by Levi]

Chemist514 - 26-1-2007 at 05:13

Quote:

Originally posted by Levi
@ Chemist514 Epsom salt (MgSO4 * 7H2O) is dirt cheap as is Washing soda (Na2CO3). To avoid paying more than you should for Sodium Sulfate you could probably make your own by desolving epsom salt and washing soda.

MgSO4(aq) + Na2CO3(aq) --> Na2SO4(aq) + MgCO3(s)

If i'm right, the magnesium carbonate will precipitate leaving you with a Sodium sulfate solution which can then be decanted and dried by heating. Anyone know for certain if this method will work?

I'll certainly try it this weekend, just let me clean up a few other things. ( no less then 3 labs are moving where i work and as a janitor that gives me much garbage.. erm i mean loot. lol) all the best!

Levi - 26-1-2007 at 07:59

I can save you the trial run as I've just attempted it myself. Epsom salts and washing soda do indeed yield an insoluble preciptate which can only be MgCO3. Large scale production of Na2SO4 can be done on your first attempt. Make sure you pour slowly when mixing the two solutions or you'll have to wait forever before you can decant. The harvested solution should be heated beyond dryness to remove all of the water and convert any NaHSO4. If you intend to keep the Mg precipitate also and are using a saturated solution you will want to pay attention to the temperature of both solutions as combining them may drop the temperature and cause Na2CO3 to fall out of the solution and contaminate your MgCO3. Hope this helps.

[Edited on 26-1-2007 by Levi]

woelen - 26-1-2007 at 10:56

How do you assure you have pure Na2SO4? Just a little too much or too little of one of the starting materials yields either contamination with Mg(2+) ions or CO3(2-) ions.

Do you recrystallize to get rid of the impurity? Both Na2CO3.10H2O and MgSO4.7H2O are not the best chems to weigh precisely (either efflorescent or hygroscopic to some extent).

UnintentionalChaos - 26-1-2007 at 13:14

Since the materials so cheap, multiple recrystallizations are very useful. You can also exploit its odd solubility curve. Chilling a boiling hot saturated solution to 5C will force about 5/6 of the Na2SO4 out of solution into crystals of decahydrate. This can be achieved in a few hours. This can then be rinsed in a filter paper with ice water to remove any remaining contaminated solution with minimal losses of Na2SO4. 3 recrystallizations turned some foul waste solutions of mine into snow white anhydrous powder.