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Making KNO3


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I read a post exactly like this before. I'm a little confused with the measurements.


KCL+NaNO3 ----> KNO3+NaCL


It's a one to one ratio i know this. The approx molecular mass of KCL=74 and NaNO3=85


74/85=0.87 It says to get the proper amount of NaNO3 I need to multiply 0.87 by the mass of KCL that choose to use. Wouldn't it be the other way around? That I multiply the mass of the NaNO3 I use by 0.87 to determine the mass of KCL I need? Any help appreciated.

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You need to use the formula:


amount (moles) = molecular mass / mass of the molecule


You know it's a 1:1 ratio. That's a molar ratio. That is, you want 1 mole of KCl to react with 1 mole of NaNO3.


In the reaction:

2H2 + O2 --> 2H2O

It's a 2:1 ratio of hydrogen to oxygen. So you want 2 moles of hydrogen for every mole of oxygen.


"The approx molecular mass of KCl=74 and NaNO3=85" I'll take your word for that... now you want a ratio of how much mass to how much mass. To start off with we have a molar ratio of 1:1.



amount = molecular mass / mass

the molar ratio could be written as:

(RFM is relative formula mass, it's the same as molecular mass)

(RFM / mass) : (RFM / mass)


(74 / massKCl) : (85 / massNaNO3)


Moving the 85 over to the other side:


(74 / 85*massKCl) : (1 / massNaNO3)


74/85 = 0.87


(0.87 / massKCl) : (1 / massNaNO3)


flipping both the fractions over:


(massKCl / 0.87) : (massNaNO3 / 1)


(massNaNO3 / 1) is just (massNaNO3)


(massKCl / 0.87) : (massNaNO3)


So you take the mass of KCl you have and divide it by 0.87 to get the mass of the NaNO3.




Moving the 0.87 over gives:


(massKCl) : (0.87*massNaNO3)


So take the mass of the NaNO3 and multiply it by 0.87 to get the mass of KCl you need.


Hopefully that helps.

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Thanks for clearing it up for me, guess I knew what to do but not the proper mechanics behind it which you just showed to me. Can you recommend any websites that can explain to me how to extract KNO3 from fertiliser? Or any method that requires the easiest aquirable materials? Thanks again. (want to make a smoke bomb...safely lol)

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mmm saltpeter sounds delicious...jk. I'm going to check and see if the local pharmacy would sell me saltpeter seeing that it would be the easiest route. KCL and NaNO3 sounds easier than the other methods I've read about. I did a search but I think I need to ask where am I going to get KCL and NaNO3. :) I have a suspicion they don't sell them in the pharmacie ;)

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I`m picturing Nothing off topic actualy, I Thought we were talking about Chemistry?


the reason I asked is that some countries don`t stock the same things as others, anyway.... those are you main routes towards KNO3.

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