Sciencemadness Discussion Board

What to do with sodium sulfate?

Thanatops1s - 24-7-2013 at 09:57

Basically I have a bunch of sodium nitrate leftover from nitric acid production. Does anyone have any suggestions for some sort of practical use for it?

Variscite - 24-7-2013 at 10:29

NaSO4 or NaNO3?

Hexavalent - 24-7-2013 at 10:46

Variscite, the formula of sodium sulfate is Na<FONT COLOR="red">2</FONT>SO4.

Sodium sulfate may be nice for the beginning chemist to practice precipitation reactions etc., determining experimentally which sulfate compounds of which cations are soluble and which are insoluble. Other than that, I've never used it that much, although it is extremely useful in organic chemistry, when anhydrous, for drying organic solutions and solvents, where calcium chloride, sodium hydroxide, alkali metals or magnesium sulfate, for instance, are incompatible or ineffective with the compounds involved.

In hindsight, are you certain that you do not have sodium <FONT COLOR="red">bi</FONT>sulfate, following your nitric acid synthesis? The latter will have a lower melting point and higher pH than regular Na2SO4, and can be used as a substitute for dilute sulfuric acid in many applications, where it may be a safer alternative (I recall a chemistry set I used to have contained a small vial of it, and it was used as an acidic solution for the experiments.))

I've almost never needed to use sodium nitrate in an experiment, and never do anything pyrotechnics-related, so I can't really suggest a common application for it in the amateur lab. Of course, you may find the odd use/purpose for it, so it is worth keeping, but I wouldn't say it is an essential chemical for the amateur.


[Edited on 24-7-2013 by Hexavalent]

papaya - 24-7-2013 at 10:59

Are you sure it's sulfate and not bisulfate ? What is the melting point of it? If it's bisulfate (or contains reasonable amount of it) it can be used instead of diluted sulfuric acid in some cases. Sulfate can serve as a good dessicant for liquid organics after being roasted.

Thanatops1s - 30-7-2013 at 16:08

I'll have to check the melting point of it. It's some really beautiful looking needle shaped crystals. If nothing else, it looks really cool the way it crystallized on the bottom of the beaker.

vmelkon - 31-7-2013 at 12:04

Quote: Originally posted by Hexavalent  
In hindsight, are you certain that you do not have sodium <FONT COLOR="red">bi</FONT>sulfate, following your nitric acid synthesis? The latter will have a lower melting point and higher pH than regular Na2SO4, and can be used as a substitute for dilute sulfuric acid in many applications, where it may be a safer alternative (I recall a chemistry set I used to have contained a small vial of it, and it was used as an acidic solution for the experiments.))
[Edited on 24-7-2013 by Hexavalent]


The pH will be lower. NaHSO4 acts as an acid.

Na2SO4 can be used as a drying agent in organic chemistry, but besides that, I don't see any major use.
Perhaps you can heat it with carbon at some high temperature and obtain Na2S. This can be used to test the presence of lead ions at very low concentrations.

AndersHoveland - 31-7-2013 at 21:36

Perhaps heat it with charcoal, reducing it to sodium sulfide?

Oscilllator - 2-8-2013 at 01:18

you could react it with sulfuric acid to make sodium bisulfate:
H2SO4 + Na2SO4 -> 2NaHSO4
and then turn it into Oleum :D

Thanatops1s - 4-8-2013 at 16:45

Looks like I do have sodium bisulfate. I think for the immediate future, I'm just going to hang onto it. I just hate wasting chemicals. I always like to find a use for everything I can. Not only because of the money issue, but I just hate throwing away anything at all that could be useful at some point(my collection of computer parts is obscene).