How to Make Sodium Nitrate, a Potassium Nitrate Substitute

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Introduction: How to Make Sodium Nitrate, a Potassium Nitrate Substitute

About: NurdRage is a dedicate group of science nerds trying to further amateur science with direct how-to instructions in video format. We saw what was already online and we thought "we could do better".....

How to make sodium nitrate, which can substitute for potassium nitrate for most purposes.

Note: Sodium Nitrate is somewhat hygroscopic. Stuff you make from it such as pyrotechnic compositions should be used soon after making and not stored for extended periods of time.

WARNING: Both procedures produce large quantities of ammonia gas. You have to do this experiment outside or in a fumehood.

First get ammonium nitrate from an instant cold pack as seen in our previous video: http://www.youtube.com/watch?v=6iMeBxNcZf0

For the baking soda method. Get 80 grams of ammonium nitrate and dissolve it in 150mL of water. Filter it off directly into 84 grams of sodium bicarbonate, which is baking soda. Then boil the mixture down to 100mL or less. This is needed to decompose the ammonium bicarbonate that's formed. It cannot be skipped. The boiling will release large amounts of ammonia so you have to do this outside or in a fumehood. Once it's boiled, leave it to evaporate until dry.

For the sodium hydroxide method: Place 80 grams of ammonium nitrate in a tall container and pour 40 grams of sodium hydroxide on top. Then carefully pour 30mL of water and stand back. It will quickly react to generate ammonia gas and sodium nitrate. Stir the mixture to make sure it's completely reacted and then add another 50mL of water and stir until dissolved. Filter it out and let the clear solution evaporate.

Both methods will produce pure sodium nitrate.

To test the sodium nitrate for reactivity just mix it with an equal amount of sugar and set it on fire. Sugar does not burn by itself but with sodium nitrate it will burn with a bright yellow flame.

Sodium hydroxide is also known as Lye, Caustic Soda, or "Red Devil Lye" and can easily be purchased online.

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    67 Discussions

    Idea for preservation of finished powder: Put finished powder in an airtight container, then put an open container of borax in with it, then seal. don't mix the two.

    can you use ammonia nitrate instead of potassium nitrate to make black powder using the same basic recipe: 75% nitrate; 15% charcoal; 10% sulfur?

    the Ice packs that I have say that they are sodium nitrate already is there a prosses to make this purer or more potent? cause it is not flammable with surger as in the video I'd appreciate the help!

    4 replies

    Re-Crystallization... It would also need to be ground up finely, but chances are if your using the stuff strait from the Cold Back that the outside of the Prills are coverd with some Anti-Caking agent, which more then likely doubles as a fire retardent...

    Yeah actually, typically in any pyrotechnic composition, purity tends to be fairly important.

    Thank you for this informative Video NurdRage, I am sorry that you are unable to continue to make videos... But Know that I have learned a lot from the ones you did make, and that It is all greatly appreciated!!

    about how long estimated would it take for the liquid to evaporate in the ammonium nitrate/ sodium hydroxide method?

    1 reply

    That would matter solely on the conditions you have it in... In a jar it could takes months... In a large pan left in the sun it could take days... So one could not give you an estimate that could even remotely be accurate without more information...

    at the moment I have a white substance at the bottom of the jar and a liquid over top of it. Its only been a day for evaporation but there are no crystals yet. When I boiled the solution I could smell the ammonia, so I assume things were going OK. does this sound like I'm on the right track?

    1 reply

    You would have to boil the solution until you smelled absolutely no more Ammonia for this to work fine... But other then that It would seem everything would be fine...

    i tried sodium nitrate/icing sugar mix in small model rocket engine tube, and it didn't work really well, i think NaNO3 doesn't burn fast enough to work in rockets or r candy. but you can try that yourself ofcourse. But if you add some aluminium powder to NaNO3/sugar mixture it will burn faster. i tried that and it burned a lot faster, and brighter.

    2 replies

    Bare in mind, that the chemistry for black powder and rocket candy using sodium nitrate as a substitute for potassium nitrate, is a little different. for example black powder is 75:15:10 KNO3 to Charcoal to Sulfur. but using sodium nitrate the ratio amount of NaNO3 is lowered to only 69 parts by mass. The charcoal and sulfur measurments are slightly tweaked too, so google it.