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how to make kno3


SJBrady

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quote from

http://www.geocities.com/CapeCanaveral/Campus/5361/kno3/ammnit.html

 

 

You can scale the following up or down.

Take 760cc (760g) of water and heat to about 50C. To this water add 3 mole (223.5 grams) of your recrystalized and dried KCl and dissolve. Add 480grams of your Ammonium Nitrate solution.

You will now have one liter of water with 3 moles of Ammonium Nitrate and 3 moles of KCl dissolved in it. Note: You won't actually have a liter of SOLUTION as dissolving the salts in the water will increase the volume.

If you are using pure Ammonium Nitrate (you did not bother with the 50% solution above) you should take one liter of water, 223.5grams KCl and 240grams solid (pure) Ammonium Nitrate.

All of the salts will be dissolved and if not the solution should be heated more untill they are.

The solution is now cooled slowly, the slower the better. Slow cooling gets you larger crystals of KNO3 which is desirable as they wash better. When the solution has cooled to room temperature it should be placed in the freezer and cooled to about -12C. Don't let any ice form. If you don't have a freezer it is ok but will get much less KNO3 out, in fact you can improvise your own "freezer" by making a freezing mixture of Ammonium Nitrate and water and putting the container which has your solution sitting in it.

The KNO3 will come out of solution. The KNO3 can now be seperated out by filtering through a cloth. The crystals should be squeezed when then are in the cloth to get rid of as much of the liquid as possible. The crystals can now be washed in cold (0C) water by simple putting the cloth containing the crystals into the cold water and moving it up and down a number of times so that the water flows in through the cloth to the crystals. The cloth, still with the crystals in it, it taken out and squeezed so that as much of the washing water is got rid of. The yield of KNO3 is about 175 grams KNO3. The KNO3 should be recrystallized for maximum purity.

The liquid that the KNO3 has come from will have KNO3 and Ammonium Chloride dissolved in it and this can be saved if you want to attempt to take out some Ammonium Chloride from it later. The Ammonium Chloride would be useful if you were making Ammonium Perchlorate from Sodium Perchlorate....but thats another story.

 

 

 

 

 

could i use CaNO3 instead of nh4no3 in the making KNO3

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could i use CaNO3 instead of nh4no3 in the making KNO3

 

Certainly, in fact the Calcium route is preferable, as there`s a greater difference in solubility, CaCl2 is roughly twice as soluble as NH4Cl, giving you a larger window to crystalise out your product.

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If you have potash instead of KCl, then making KNO3 is even easier.

 

Just mix the two chems, add a little water, and heat. Ammonia and carbon dioxide will be driven off, what remains is KNO3 and water. On continued heating, the water also is driven off.

 

2NH4NO3 + K2CO3 --> 2KNO3 + 2NH3 + CO2 + H2O

 

Try to use a slight excess of K2CO3, but only a slight excess. You have the reaction equation, so you should be able to determine the right ratio of the chemicals. Keep in mind that NH4NO3 usually is somewhat humid, so it is best to dry that before doing the reaction, by putting it on a hot radiator for some time. This makes weighing more accurate.

 

Having a slight excess of K2CO3 makes KNO3 with some K2CO3 left in it. That stuff is better and reacts more vigorous than pure KNO3.

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as with the above, but it`s best to Boil the soln as that breaks down any Ammonium Bicarbonate formed by the decomposition ammonium carbonate itself.

 

you may be interested to note that I make All my KNO3 by this process, it makes a VERY GOOD plant food for my Chilis and Tomatoes :)

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Sorry, I forgot about the Ca(NO3)2 you have, I was thinking about NH4NO3, which is the more common fertilizer.

 

Using Ca(NO3)2 also works. It, however, is somewhat more messy, but with patience you should be able to do it.

 

Add a solution of Ca(NO3)2 to a solution of K2CO3, again in the right ratio. In this case, a 1:1 molar ratio. When these are brought together, a precipitate of CaCO3 is formed, which settles at the bottom, and KNO3 remains behind in solution. Let this precipitate settle and decant the clear liquid from the precipitate and evaporate this to dryness. The liquid then is evaporated and you obtain your solid KNO3. If you want it really pure, recrystallize once from a small amount of hot distilled water.

 

Again, use a slight excess of K2CO3, you don't want much calcium remaining in your KNO3, it makes your KNO3 very hygroscopic, because Ca(NO3)2.xH2O is very hygroscopic.

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Lookup the atomic weight for the different elements and compute it yourself. There are plenty of tables on the Internet with their values, or look up a text book. A good source of info is http://www.webelements.com. Click one of the elements and you get a table with all kinds of useful info, including the atomic weight.

 

If you present the calculations over here, I will tell you whether they are correct or not, but I am not going to spoonfeed you with the values.

 

Keep in mind that for Ca(NO3)2 the situation is much more complicated than theory suggests. In reality you won't have Ca(NO3)2, but some hydrated form, Ca(NO3)2.xH2O, with x being highly variable. The material can also be quite humid, it is hygroscopic, increasing its water content even more. This makes accurate weighing of a certain amount of Ca(NO3)2 quite difficult. The best thing you can do is take the Ca(NO3)2.xH2O and heat it until it starts glowing dark red. You weigh the amount before heating, and you weight the amount after heating. After heating only CaO is left, all other things are left. In Ca(NO3)2.xH2O, the ratio of Ca(2+) to NO3(-) will always be 1 : 2, so you can compute how much Ca(NO3)2 is contained in 1 gram of Ca(NO3)2.xH2O.

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