Can you use nitric acid + sodium hydroxide to make sodium nitrate?

I am trying to make some small rockets and I can't get or make KNO3 (It's banned and I can't find potassium chloride in any supermarkets, if you know where to find it please tell) so I have been making sodium nitrate out of ammonium nitrate and sodium hydroxide as a substitute, so in trying to make the process cheaper I have found this HN03 + NaOH = NaNO3 + H2O will this work?


sort by: active | newest | oldest
andy707076 years ago
Which country do you live in? It's easy enough to get KNO3 in the UK or the US. As for your question, it would work, but you will make very small amounts so it may be quite expensive. You will also need to filter and evaporate the solution to get the NaNO3 crystals. I would also recommend that you instead use pre-made engines such as estes. They work out roughly the same price or cheaper than home made fuel, there's no legal issues, and they are guaranteed to give good results. I spent ages trying to get a questionably legal mixture using KNO3 to work, and they would often not ignite and max height was only about 10 metres. When using an estes engine, I achieved about 350m, so now all further rockets will use estes motors instead.
The MadScientist (author)  andy707076 years ago
Australia has strict bans on KNO3. Example: 30% is the maximum allowed in any fertiliser.

Say I used 1L of pure nitric acid with the appropriate amount of NaOH how much NaNO3 would I get.
What do you mean by "pure"? Acids have to by dissolved in water, so cannot be entirely pure. Fully saturated acids are hard to come by, if thats what you mean. Anyway, I'll tell you how to work it out, assuming 1M HNO3. HNO3 + NaOH -> NaNO3 + H2O. The molecular masses for the compounds would be 63, 40, 85, and 18 respectively, so I'm pretty sure that means you will produce 875.5g NaNO3, assuming excess NaNO3 to acid. I might be wrong though, and it gets harder if you change the volumes and moles.
Actually, I'm pretty sure it's just 87.55g.
The MadScientist (author)  andy707076 years ago
By pure I mean 100%.

1M?
Also, it is 85g, according to Wolfram Alpha. It also shows that using 5M Nitric Acid will give a much larger yield of 425g here. Wolfram Alpha is a good tool to use when it comes to things like this, I just did the calculations roughly this morning. From a quick google search, it appears the highest concentration of Nitric Acid achievable before it becomes saturated is around 5.25M, so if you can find some 5M HNO3 and some high purity NaNO3. 
1M isn't pure, it's actually pretty weak. I believe for full saturation of HNO3 gas in water, it is just over 5M. It cant be pure as it needs to be dissolved in a gas to be acidic. Pure gaseous HNO3 won't be acidic unt dissolved in water.
AvirajS1 year ago

I am not sure but i think it's not pure...

http://platinumflooringcompany.com/

you can buy potassium nitrate from farm supply houses in australia. you will have to provide a reason for your requirments and produce ID. this is because, like everything in this anal land, its restricted material. I rang round this morning to find "pentane" seems i cant get that anywhere short of lab supply houses priced at australia's normal highest possible prices $78.00 for 500ml (yes, you read that right) and seems now even sodium hydroxide is banned too! great, in the same week i am building a hho and hydrocarbon smith little torch system that uses sodium hydroxide. so typical.. i should have known my infintile little knee-jerk country would have done some typical stupid move to screw me on that too... im over australia... so so so useless all the time. in fact, it is this countrys only consistancy.

you can buy potassium nitrate from farm supply houses in australia. you will have to provide a reason for your requirments and produce ID. this is because, like everything in this anal land, its restricted material. I rang round this morning to find "pentane" seems i cant get that anywhere short of lab supply houses priced at australia's normal highest possible prices $78.00 for 500ml (yes, you read that right) and seems now even sodium hydroxide is banned too! great, in the same week i am building a hho and hydrocarbon smith little torch system that uses sodium hydroxide. so typical.. i should have known my infintile little knee-jerk country would have done some typical stupid move to screw me on that too... im over australia... so so so useless all the time. in fact, it is this countrys only consistancy.

you can buy potassium nitrate from farm supply houses in australia. you will have to provide a reason for your requirments and produce ID. this is because, like everything in this anal land, its restricted material. I rang round this morning to find "pentane" seems i cant get that anywhere short of lab supply houses priced at australia's normal highest possible prices $78.00 for 500ml (yes, you read that right) and seems now even sodium hydroxide is banned too! great, in the same week i am building a hho and hydrocarbon smith little torch system that uses sodium hydroxide. so typical.. i should have known my infintile little knee-jerk country would have done some typical stupid move to screw me on that too... im over australia... so so so useless all the time. in fact, it is this countrys only consistancy.

frankiedog5 years ago
you can concentrate the 30% kno3 easily by punting it and hot water untill it reaches satoration then cooling it down to recrystilise nurd rage would have an instructible on recrystalazation
I don't know where you live, but here in the Former US, you can find KCl in 40 pound bags, as a kind of water softener salt. I mean it doesn't soften water by itself, but you feed it to a water softening appliance, and this performs some ion-exchange voodoo using magic "zeolite" crystals, and voila: soft water. For example:
http://www.homedepot.com/webapp/wcs/stores/servlet/Search?keyword=Potassium+Chloride

That's just one store. A lot of grocery stores, hardware stores, department stores, have it too.  For some reason the KCl is typically 3 to 4 times as expensive as the NaCl.  So if they're asking 5 USD per bag for ordinary NaCl salt, then its like 20 USD for one bag of the KCl salt.  The good news is, unless you're doing things on an industrial scale, that one bag should last a while.

I dunno.  There's some seriously funny business going on in the world today with respect to buying chemicals on the street.  Essentially everything that's out there in stores is intended as some sort of consumable good, rather than a raw material.  A consumable good is something that is intended to be sold unto a consumer, so that he or she can take it home and flush it down the toilet, or quickly break it, thus necessitating that he or she come back to the store, and buy another one of those things.

And it was for that reason that I thought there would always be pure NaOH lye, available in stores, sold as drain opener.  Because that's one of those products that is sold to be flushed down the toilet, or the sink, whatever.  It goes to the same place.

But the dang thing is: they stopped selling pure NaOH drain opener at the stores in my town!  Sure they still sell "drain opener", but now its a witches brew of NaOH adulterated with cheap NaCl, and little green crystals that don't actually do anything except  appear green and sparkly.

So if you can still find ammonium nitrate and sodium hydroxide in stores, consider yourself lucky, and uh... stock up, because it probably won't be available in the future.

Regarding the reaction: HN03 + NaOH = NaNO3 + H2O
That should work, maybe too well.  I mean you should calculate how much heat (enthalpy) is going to be involved, because it might be enough to boil the water and making the solution spashy and dangerous.

But where are you going to get nitric acid?  I mean if sales "associates" give you funny looks when asking about KNO3, how are they going to feel about nitric acid?

They might just call John Elway.  Yeah. I know.  Those control-freak bastards! They got to John Elway too!  Just look at him now:
http://www.youtube.com/watch?v=--bgb2SMpZo
Brainwashed.  I know there probably wasn't much brain there to wash in the first place, but it's still pretty disappointing.
Check with a local plumbing supply business. I bought a 2 pound container of pure lye (sodium hydroxide) crystals last summer and as I recall, it is available at most of the plumbing supply companies I have used in the past.
Thanks for the tip.  I found some pure NaOH drain opener, today, so I guess that means it's not as hard to find as I thought it was...  and it might be the case that part of the problem was negative thinking on my part; i.e.  I couldn't find it because I wasn't expecting to find it, because of that previous occasion when I couldn't find it... 

I'm not sure I want to admit which store I found it in, but honestly it was hiding in plain sight. 

As a way to try to atone for some of my previous bitching and moaning (about not being able to find NaOH, in a brick-and-mortar-store, in the Former U.S.), some pictures of this product (Roebic(r) Heavy Duty Crystal Drain Opener(r) ) and a link to the MSDS are attached.

For anyone else seeking this stuff out.  The clues are on the label.  It claims, in writing, to be pure NaOH.  Also looking at the substance itself, it appears white, crystaline, homogenous.  No funny blue color, or little pieces of aluminum, like are often found in the "witches' brew" brands.

pictures:
https://www.instructables.com/file/FB50MF6GVWZ3YOT/
https://www.instructables.com/file/FYIXRPHGVVPD0GX/
https://www.instructables.com/file/F1AYOHOGVVOVKWJ/

MSDS:
http://www.roebic.com/pdf/hdcryMSDS.pdf
roebic_pure_naoh_drain_opener-pic1.jpgroebic_pure_naoh_drain_opener-pic2.jpgroebic_pure_naoh_drain_opener-pic3.jpg
Yep, that's precisely what I bought. I got it at Lowe's plumbing dept. but I've seen it at Home Depot too.
The MadScientist (author)  Jack A Lopez6 years ago
I'll have another look for KCl, I can still get 98% NaOH (it's in every supermarket) and nitric acid I can get 40% pure at hardware stores ($25 for 5L).

Thanks for the answer!