Vikascoder
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40%nitric acid to 70%
I have used the search engine and searched on sciencemadness but i didnt find any reliable source how to concentrate 40%nitric acid to 70%or higher
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AndersHoveland
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You can add concentrated sulfuric acid (90-98%) to absorb the water, then extract the nitric acid from the concentrated acid mixture using methylene
chloride. Methylene chloride is commonly found in solvents available in automotive stores.
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UnintentionalChaos
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Quote: Originally posted by AndersHoveland  | | You can add concentrated sulfuric acid (90-98%) to absorb the water, then extract the nitric acid from the concentrated acid mixture using methylene
chloride. Methylene chloride is commonly found in solvents available in automotive stores. |
Your title is as relevant as ever.
Put a fractionating column (for best results, though simple distillation will work as well) and distill until the stillhead reaches 120C, the boiling
point of the ~69% nitric acid azeotrope. The distillate should be almost entirely water with traces of acid (significantly more acid will be wasted
this way without the column). The liquid in the stillpot is the more concentrated acid.
As a PS, nitric acid attacks the rubber typically used for thermometer adapters...I have one with a fluoroelastomer gasket that is fine. An IR
thermometer might be able to hazard a decent guess.
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'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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weiming1998
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| Quote: Originally posted by Vikascoder | | I have used the search engine and searched on sciencemadness but i didnt find any reliable source how to concentrate 40%nitric acid to 70%or higher
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You have two options:
1, Distil the acid to its azeotrope
2, Neutralize the acid with a suitable base, evaporate the water, then add concentrated sulfuric acid. If you want 70% acid only, you can add 30 ml of
water per 70 ml of acid.
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Pulverulescent
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| Quote: | | Your title is as relevant as ever. |
There's a whole lot of shakin' going' on, but it's taking hours and hours to get nofuckingwhere!
My arms are aching at just the thought of it . . . | Quote: |
I have one with a fluoroelastomer gasket that is fine. |
Yeah! They're great ─ but sooo fucking losable ─ then it's back to the reliable old teflon tape . . .
Always keep a roll or twenty handy!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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Pulverulescent
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| Quote: | | Neutralize the acid with a suitable base, evaporate the water, then add concentrated sulfuric acid. If you want 70% acid only, you can add 30 ml of
water per 70 ml of acid. |
You don't need the nitrate salt!
40% HNO<sub>3</sub> can be brought to >90% by distilling from 150% its volume of H<sub>2</sub>SO<sub>4</sub>!
The sulphuric acid can then be reconcentrated by heating in a well ventilated area, a fume-cupboard or downwind of the vapours!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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weiming1998
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| Quote: Originally posted by Pulverulescent | | Quote: | | Neutralize the acid with a suitable base, evaporate the water, then add concentrated sulfuric acid. If you want 70% acid only, you can add 30 ml of
water per 70 ml of acid. |
You don't need the nitrate salt!
40% HNO<sub>3</sub> can be brought to >90% by distilling from 150% its volume of H<sub>2</sub>SO<sub>4</sub>!
The sulphuric acid can then be reconcentrated by heating in a well ventilated area, a fume-cupboard or downwind of the vapours!
P
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I assume that this works by bringing the boiling point of water to 300 degrees celsius, so that the nitric acid easily boils away? But what about the
azeotrope of nitric acid with water? The attraction between sulfuric acid and water can break an azeotrope? Or sulfuric acid disrupts the azeotrope?
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Vikascoder
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Why not to freeze than take ice out and save nitric acid why always boils and my distilling kit was attacked by nitric acid as someparts were made up
of rubber . So any other way rather distilling
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Vikascoder
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Why not to freeze than take ice out and save nitric acid why always boils and my distilling kit was attacked by nitric acid as someparts were made up
of rubber . So any other way rather distilling
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Pulverulescent
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In the distillation, strong nitric acid comes over from the soln when the temperature is held @ 120°C.
The sulphuric acid binds up the water at this temperature . . .
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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hkparker
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The methylene chloride "extraction" method was passed around on a drug forum a while ago, the actual entire procedure was extremely frightening.
Someone on youtube send it to me asking if it was ok...
Distilling out the water with a fractionating column like UnintentioalChoas said is the best method. For concentrations >70% sulfuric acid does a
good job of breaking the azeotrope, and lets you distill RFNA. Vacuum distillation at lower temperatures will produce WFNA.
My YouTube Channel
"Nothing is too wonderful to be true if it be consistent with the laws of nature." -Michael Faraday
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weiming1998
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| Quote: Originally posted by Vikascoder | | Why not to freeze than take ice out and save nitric acid why always boils and my distilling kit was attacked by nitric acid as someparts were made up
of rubber . So any other way rather distilling |
Because homogeneous mixtures are very difficult to separate by freezing! If you put the 40% nitric acid in a freezer, the water wouldn't freeze, even
if it is below 0 degrees celsius. If you get a low enough temperature, then all of the acid will freeze.
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UnintentionalChaos
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| Quote: Originally posted by Pulverulescent | | Quote: | | Your title is as relevant as ever. |
There's a whole lot of shakin' going' on, but it's taking hours and hours to get nofuckingwhere!
My arms are aching at just the thought of it . . . | Quote: |
I have one with a fluoroelastomer gasket that is fine. |
Yeah! They're great ─ but sooo fucking losable ─ then it's back to the reliable old teflon tape . . .
Always keep a roll or twenty handy!
P |
You can buy the fluoroelastomer o-rings for 15 cents each if you look in the right places. they tend to get trashed after use with halogenated organic
solvents anyway and should be replaced every once in a while.
Department of Redundancy Department - Now with paperwork!
'In organic synthesis, we call decomposition products "crap", however this is not a IUPAC approved nomenclature.' -Nicodem
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Vikascoder
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I am thinking if calcium nitrate is mixed with sulfuric 98% acid will it make nitric acid above 70 %solution and calcium sulphate which can be
filtered and then i will not need to distill the solution just . Tell me i will need to distill or nitric acid will be formed in liquid form in that
beaker. Of high concentration
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vulture
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| Quote: |
The methylene chloride "extraction" method was passed around on a drug forum a while ago, the actual entire procedure was extremely frightening.
Someone on youtube send it to me asking if it was ok... |
I performed this method, it's not frightening, it works rather well and it has been described on this forum. Certainly safer than vacuum distillation.
One shouldn't accept or resort to the mutilation of science to appease the mentally impaired.
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Pulverulescent
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Tell us more, vulture?
I'd heard it was a lot of work for little reward ─ I'm still interested, though!
P
"I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones"
A Einstein
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hkparker
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Please do tell, I too have heard very negative things but I'd be curious to see the results you got.
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"Nothing is too wonderful to be true if it be consistent with the laws of nature." -Michael Faraday
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