Sciencemadness Discussion Board - Which nitrate to buy?

Which nitrate to buy?

Sulaiman - 12-4-2015 at 00:44

I want to experiment with nitrations, I already have 96% sulphuric acid, glassware etc.
the classic nitrate to use is potassium nitrate, but now it is seen as a 'terrorist' chemical
from eBay, in order of increasing cost, I can buy;

Calcium nitrate
Strontium nitrate
Sodium nitrate
Barium nitrate
and off the affordability chart, Silver nitrate

I would like to choose the one that has the most usefulness for general chemistry

Which one should I buy and why?

[Edited on 12-4-2015 by Sulaiman]

Deathunter88 - 12-4-2015 at 02:22

Quote: Originally posted by Sulaiman

I want to experiment with nitrations, I already have 96% sulphuric acid, glassware etc.
the classic nitrate to use is potassium nitrate, but now it is seen as a 'terrorist' chemical
from eBay, in order of increasing cost, I can buy;

Calcium nitrate
Strontium nitrate
Sodium nitrate
Barium nitrate
and off the affordability chart, Silver nitrate

I would like to choose the one that has the most usefulness for general chemistry

Which one should I buy and why?

[Edited on 12-4-2015 by Sulaiman]

I would go with calcium nitrate, because quote sciencemadness wiki: Because of its hygroscopicity, it is unsuitable for use as an oxidizer in energetic mixtures; however, due to the insolubility of many calcium salts, the nitrate ion in calcium nitrate can easily be used to prepare other more useful nitrates as well as other calcium compounds. Examples of this include the addition of sodium carbonate to precipitate calcium carbonate and leave sodium nitrate in solution, or the addition of potassium sulfate to generate potassium nitrate in solution, precipitating calcium sulfate. Virtually any nitrate compound can be produced by addition of a sulfate or carbonate solution in this manner.

ISCGora - 12-4-2015 at 02:49

Only thing with Ca(NO3)2 is if you were planning to make nitric acid from it,it will be pretty painful to remove the remaining CaSO4

Since it is not soluble in water only 0,24 g/100ml at 20 °C.

hissingnoise - 12-4-2015 at 03:47

Quote:

. . . the classic nitrate to use is potassium nitrate, but now it is seen as a 'terrorist' chemical from eBay.

How so ─ ebay has massed ranks of sellers of this salt and calcium nitrate being very hygroscopic is practically useless for pyro or nitric acid distillation.

subsecret - 12-4-2015 at 06:19

I don't recommend calcium nitrate. It's like having copper (II) in the form of the carbonate; it's pretty tough to work with when you have to prepare other compounds in order to use it.

gdflp - 12-4-2015 at 06:31

Out of all the nitrates you listed, the best one to use for nitrations by far is sodium nitrate. The rest will precipitate sulfates on contact with sulfuric acid which will then make workup a pain. Yields will likely also be very low because the nitrate particles will get coated in sulfate which will prevent further reaction. Barium or strontium nitrate may be useful if you want to prepare other nitrates as sodium nitrate will not be able to accomplish this in most cases(a metathesis reaction may work in some cases but yields will still be rather low).

Bert - 12-4-2015 at 06:38

Ammonium nitrate, you can make all the others from this one (plus nitric acid...) Or use it straight up for various propellants & explosives.

Of course, check your local laws first!

gdflp - 12-4-2015 at 07:29

Quote: Originally posted by Bert

Ammonium nitrate, you can make all the others from this one (plus nitric acid...) Or use it straight up for various propellants & explosives.

Of course, check your local laws first!

Well, if potassium nitrate is banned because of it's possible use in terrorist applications, I would be very surprised if ammonium nitrate wasn't.

bolbol - 12-4-2015 at 08:05

If you really want KNO3 but don't want to order it from Ebay you can get stump removers and perform recrystallization to get a pure sample. There are videos on youtube about this as well

Etaoin Shrdlu - 12-4-2015 at 09:36

EDIT: Oh damn, you're in England.

[Edited on 4-12-2015 by Etaoin Shrdlu]

Sulaiman - 12-4-2015 at 10:52

since Sept. 2014 EU explosive precursors laws
even if I find a supplier for potassium (or ammonium) nitrate I think I'd be breaking the law by buying it,
I can keep stuff on the list until 2016 then just possessing it will be illegal.
I've downloaded the license application forms and I may apply.

I'm not worried about small amounts synthesised or refined at home,
so I'll look at other routes.

woelen - 12-4-2015 at 11:13

The law you refer to does not apply to KNO3, or NaNO3. I live in NL and we have exactly the same law since Sept. 1, 2014. The new law applies to the following 7 chemicals:
HNO3 (3% or more concentrated)
CH3NO2 (30% or more concentrated)
H2O2 (12% or more concentrated)
KClO3
KClO4
NaClO3
NaClO4

NH4NO3 already was hard to obtain before Sept. 1 , 2014, due to the regulation which came into effect after Breivik's terrorist attack in 2011.

KNO3 actually is one of the more benign chemicals and it can still be purchased without raising too much suspicion. NaNO3 is similar. Both can be purchased from eBay.

Ca(NO3)2 is a pain in the ass to work with. It forms layers of gypsum with sulfates, which are very hard to remove from glassware. The thick solid layers also may lead to hot spots, excessive bumping or even cracking of glassware when used in a distillation setup.

Kitsune1 - 12-4-2015 at 13:44

I wouldn't bother using the Calcium salt, it is more trouble than it is worth in most cases; I like using Ammonium Nitrate, it is very versatile and if it is available, it is cheap. You can make the group 1 metal nitrates from it and at the same time make Ammonium Hydroxide (if you want), Nitric Acid can be made from it too. (It is available in high quantities in Equine instant cold packs in the UK).

I really wonder how much effect these laws will have against would be terrorists; after all if someone wants something bad enough, has enough money and the wrong contacts, they will be able to. Just can't help but feel that these regulations will do little to help in the war against terror but cause disruption in small industry and amateur chemistry, In the UK I really struggle to get hold of any compound that contains Iodine due to it's use in the illicit production of Meth-amphetamine and yet the meth labs will still have a route to get it. Citric Acid is difficult to get due to it sometimes being used by heroin addicts to acidify heroin before injection, but if they can't get that, they will use vitamin c or vinegar (I don't see them banning or restricting that any time soon); instead of stopping drug abuse, it penalises people who make wine and cordials at home.

bolbol - 12-4-2015 at 14:39

Honestly none of the regulations really make much of a difference to people who use it for illegal stuff, only makes it a pain in the ass for the people who have non-illegal uses. If you really really want it you can obtain it, stuff like safrole, ephedrine, iodine, phosphorus, or even lab grade HI. Getting caught is the pain in the ass though,,

AJKOER - 12-4-2015 at 15:38

I still have access to relatively high purity KNO3 sold locally as stomp remover.
-------------------------------------------------------------------------------

However, if I did not, and wanted to prepare a nitrite/nitrate mix, an interesting new route which I may decide to test sometime in the future for feasibility/efficiency would be as as follows:

1. React a small amount of Cu, dilute aqueous ammonia and dilute H2O2 in the presence of sea salt (serves as a good electrolyte) and NaOH (or possibly Na2CO3) to maintain the pH over 7. The primary electrochemical reaction has associated side reactions including the formation of a small amount of NH4NO2, hopefully stabilized by the presence of the NaOH.

2. The nitrite created will serve as a source generator of hydroxyl radicals under photolysis in this second step (but if this fails, maintaining a H2O2 presence may work). Add more aqueous NH3 as the dilute ammonia is attacked by the OH radicals and eventually transformed into NH4NO2 and NH4NO3 under the action of sunlight.

3. Stop when the amount of dilute ammonia added and reacted under photolysis in the presence of the nitrite catalyst brings you to your total target yield. Then, add for example, Na2CO3 or NaOH, to extract by heating NaNO3. Caution: never attempt to work with a concentrated ammonium nitrite solution, or one that is acidified, as even such aqueous solutions have been reported to present an explosion hazard!

I already known the reference sources, which I will present when (and if) I post and have verified this potentially slow, but endless low cost nitrate path from common chemicals and sunlight.

Here, however, is one of the key references, see http://www.researchgate.net/publication/23495784_Removal_of_... , to quote from the abstract:

"In this research work, H2O2 was selected as *OH precursor. The removal of ammonia under 253.7 nm irradiation from low-pressure mercury lamp in the presence of H2O2 was studied to investigate the ammonia removal efficiency by *OH. Results show that the *OH, generated by H2O2 photolysis, could oxidize NH3 to NO2- and further to NO3-. Removal efficiencies of ammonia were low and were affected by initial pH value and ammonia concentration. Laser flash photolysis technique with transient absorption spectra of nanosecond was used to investigate the oxidation pathway and kinetics of ammonia oxidation by *OH. Results illustrate that *OH could oxidize NH3 to form *NH2 with a second-order rate constant of (1.0 +/- 0.1) x 10(8) M(-1) s(-1) (20 degrees C). *NH2, the main product of *OH with NH3, would further react with H2O2 to yield *NHOH. Since *NHOH could not stay stable in solution, it would rapidly convert to NH2O2- and consequently NO2- and NO3-. "

The body of the paper appears to suggest that ammonia conversion was highest at pH 9.3 where molecular ammonia concentration as NH3 equals the cation NH4+ concentration. Further, increase initial ammonia concentration increases the amount of nitrate formation, whose rate of formation declines as the solution becomes more acidic (thereby implying the need for periodic addition of ammonia, H2O2 and NaOH to target pH 9.3 to maximize yield, which may, nevertheless, be low).

Source: Environ Sci Technol. 2008 Nov 1;42(21):8070-5, "Removal of ammonia by OH radical in aqueous phase", by Huang L1, Li L, Dong W, Liu Y, Hou H.

[Edited on 13-4-2015 by AJKOER]

aga - 12-4-2015 at 15:44

The UK seems to apply each insane EU ruling with great Gusto.

Probably the UK's EU discount is involved.

Bert - 12-4-2015 at 17:23

Given the choice between Potassium, Sodium or Calcium nitrates as the only ones not requiring a permit?

Sodium nitrate if I intended to make nitric acid or perform a Sulfuric acid/nitrate nitration, such as synthesizing picric acid from aspirin.

Potassium nitrate if I had an interest in pyrotechnics.

Calcium nitrate if I wished to be able to manufacture either of the above nitrates easily from OTC materials, and also provide my tomato and pepper plants a nice water soluble fertilizer to boost vegetative growth and inhibit blossom end rot (caused by low Calcium after a heavy rain)

jock88 - 13-4-2015 at 12:32

You can purchase 'Calcium Ammonium Nitrate' , aka CAN , or '27% straight Nitrogen' or '27.5% straight Nitrogen' from any farm store by the cwt.
It's a mixture of Ammonium Nitrate + Lime of some sort (insoluble).

woelen - 13-4-2015 at 13:23

This product, called KAS where I live, cannot be purchased anymore by people without a license. Only farmers who can show that they need it as fertilizer can still buy this, but it requires paperwork. I as a plain consumer cannot buy KAS (kalk ammon salpeter, translated as chalc ammonium saltpeter) anymore since four years ago.

Sulaiman - 13-4-2015 at 14:07

I've decided, I ordered calcium nitrate as I want to have a go at synthesising other nitrates
from a simple source, and I can use it as a fertiliser ... thanks Bert

a workmate gave me 15.22g KNO3 he had left over so enough for a trial run.

Thanks for all of the info.

Texium - 13-4-2015 at 14:45

The calcium sulfate formed is actually not a bad thing as long as you can stir the contents of the flask. Because it precipitates out all of the sulfate, you'll generally get a better yield than using the soluble ones, and calcium sulfate is also hygroscopic, so it will also sequester some of the water.

Praxichys has a video explaining all of this in greater detail. He used calcium ammonium nitrate, but the same principle applies when using normal calcium nitrate: https://www.youtube.com/watch?v=7akk5ppJjEw

Blunotte - 13-4-2015 at 23:38

This route is too hard?

First:
Ca(NO3)2 + K2CO3 --(acq)--> CaCO3 (prec) + 2KNO3

Second:
filter and evaporate the solution

Et voilà, KNO3 without troubles

If you work at 20°C, you will need about 420 gr of K2CO3 and 500 gr of Ca(NO3)2 for every liter of water:
320g/l is the solubility in water at 20° of the KNO3, but the other reagents are much more soluble

woelen - 14-4-2015 at 00:15

I am afraid that it will be a terrible mess. Do not expect to obtain a nice clear liquid with a compact precipitate in it. At those high concentrations you most likely get a white viscous mud, which will be very hard to handle. If you do this, you need much more dilute solutions, but that has the disadvantage of having a lot of water to evaporate.

If you perform this reaction, then I would take a small excess amount of K2CO3. The KNO3 you obtain then contains some K2CO3, but you can separate that fairly easily by means of recrystallization.

Keep in mind that K2CO3 is hygroscopic and the commercial material may contain quite some water, even if it looks dry. You may have to dry it in a hot oven before using it in an experiment like this if you want accurate weight measurements.

Ca(NO3)2 is available as the tetrahydrate and anhydrous. Test this before doing the experiment. Heat some of the solid in a test tube and see how much water vapor (which forms big drops of water higher up in the test tube) is formed. The anhydrous salt hardly produces any water, the hydrated salt forms quite a lot of big drops of water.

Blunotte - 14-4-2015 at 01:10

Mmm...
Yes, it's right

In these days I will want to buy some calcium nitrate and some potassium carbonate, so I will try to make it

For the eavporation, I don't think that somebody need tons of reagents, but much less than a kilo, I hope, so there is not a trouble for it

Blunotte - 14-4-2015 at 01:18

Potassium nitrate is perfect for recrystallization:

Solubility in water:
133 g/l (0 °C)
320 g/l (20 °C)
2470 g/l (100 °C)

So, just boil the solution, to evaporate some of the water, and then put in the freezer.
I think it is better to repeat this process several times, rather than do it in one go

woelen - 14-4-2015 at 05:52

One recrystallization is enough to get a nice pure product.

After boiling down, first let it cool to room temperature before putting it in the freezer. The slower the cooling down, the larger and nicer your crystals will be and the easier it will be to decant the liquid from the crystal mass. You also must not boil down so that the solution is saturated at the boiling point. If you do that, then you get very fast crystallization, leading to small crystals and less pure crystals.

Blunotte - 15-4-2015 at 07:01

Argh, I cannot find here the potassium carbonate, I have only sodium bicarbonate, but it's solubility it's very low :mad:

So I need some time for this experiment, sorry

Bert - 15-4-2015 at 07:50

Quote: Originally posted by Blunotte

Argh, I cannot find here the potassium carbonate, I have only sodium bicarbonate, but it's solubility it's very low :mad:

So I need some time for this experiment, sorry

Find wood ashes, or charcoal ashes. Do a water extraction...

http://faculty.rmc.edu/jthoburn/ChemArt/EX03.Potash.pdf

Been done since dawn of civilization-

[Edited on 15-4-2015 by Bert]

Sulaiman - 15-4-2015 at 14:56

just planning for RFNA / WFNA synthesis via
Ca(NO3)2 + H2SO4 = 2HNO3 + CaSO4
and I have questions ...

1) since the calcium sulphate precipitate may mess up my distillation flask
is there any reason why I should not perform the reaction in a beaker
then decant the liquid into the distillation flask ?

2) one mole of calcium nitrate = 164 g
requires one mole of sulphuric acid = 98 g = c56 ml of 96% H2S04
if I bake the calcium nitrate above 130 C to get the anhydrous form
how much excess sulphuric acid do I need for the drying part?
(my inclination is to use c100 ml total but I'd like to know how to calculate it)

3) I have a small vacuum pump for filtrations on order
http://www.ebay.co.uk/itm/311057103383?_trksid=p2060353.m274...
if I use this (with a NaOH trap) and it does produce its advertised -80 kpa
(21 kpa absolute, c160 mm Hg)
the nitric acid should boil at about 45 C ... is it worth the effort ?

violet sin - 15-4-2015 at 15:43

@ Blunotte: Potassium carbonate can be made from cream of tartar according to wiki( almost bottom of the page). Should be able to find that in a store, I got some from the bulk bins for cheap. Think a couple pounds of it was less than 5$ US in this way.