Oxidation Of Ammonia

[olmpiad]

Does anybody know how to oxidise ammonia? I need nitric acid very badly. Thanks!

[Dave]

Moved to the Chemistry forum; seems more appropriate

[budullewraagh]

yes, i know how to. why do you need nitric acid?

[olmpiad]

i need nitric acid to etch a meteorite (iron)

[budullewraagh]

ok, well:

at 800-900 celsius and with a platinum or rhodium or Pt/Rh catalyst, NH3 is oxidized by atmospheric oxygen to form nitric oxide. the NO is immediately oxidized to NO2/N2O4, which can be bubbled into solution, forming nitric acid and more nitric oxide.

[bigboi]

what does that mean "it would be oxidized"

[Mendelejev]

http://www.epa.gov/ttn/chief/ap42/ch08/final/c08s08.pdf

 

go check this site. But i think it's to industrial. Why do you want to make your nitric acid with ammonia ?? There are several other ways.

[budullewraagh]

well he could make a birkeland-eyde reactor, but that's a bit tricky. at the same time, so is this.

 

if you really want nitric acid, i suggest you make the anhydride by reacting conc H2SO4 with a nitrate salt.

 

NOTE: THIS REACTION YIELDS THE VERY, VERY TOXIC ANHYDRIDE OF NITRIC ACID; N2O5. MAKE SURE YOU HAVE A COMPLETELY CLOSED APPARATUS AND USE ONLY PTFE/GLASS TUBING, LEST THE TUBING BE OXIDIZED AND CORRODED AWAY. MAKE SURE YOUR TUBING LEADS BELOW THE SURFACE OF THE WATER IN YOUR SECOND BEAKER AND MAKE SURE IT WILL NOT BE PUSHED OUT FROM UNDER THE SURFACE WITH THE INITIAL PRESSURE. ALSO, KEEP THE SECOND BEAKER IN A CLOSED ENVIORNMENT.

 

sorry to yell, but it's very, very important that you know all this.

[Mendelejev]

well he could make a birkeland-eyde reactor

 

LOL !!! Yeah, that would work

 

But, yes indeed, nitric acid can be made by dissolving 2 parts Potassium nitrate (KNO3) in 1 part 98% Sulfuric acid (H2SO4) by volume, and distilling this mixture at 55-60 degrees Celsius until only a white crystalline mass, Potassium sulfate, remains in the reaction vessel. Very pure HNO3 can be made using this method.

 

Or you could make NO2 first. (Nitric acid is made by mixing nitrogen dioxide (NO2), with water. Creating a very pure nitric acid usually involves distillation with sulfuric acid, as nitric acid forms an azeotrope with water with a composition of 68% nitric acid and 32% water.)

[olmpiad]

well, how would i go about making potassium nitrate

[budullewraagh]

"LOL !!! Yeah, that would work "

ive seen pictures of working birkeland-eyde reactors made by amateurs.

 

a 1:1 ratio of H2SO4/XNO3 works as well. note that NH4NO3 isnt so effective.

 

just buy potassium nitrate

[budullewraagh]

ah, just a note about the nitric anhydride; it is volatile and sublimes at around 32 celsius. however, it is only stable below -10 celsius, so it will rapidly decompose to yield NO2/N2O4 and O2. it is soluble in chloroform and moderately so in carbon tetrachloride. such solutions are reasonably stable for short amounts of time, so long as they are kept cold.

[jdurg]

If you need to etch iron, hydrochloric or sulfuric acid will do a dandy job of that.

[H2SO4]

or maybe even copper sulfate solution, then just rub the Cu dust of it.

[olmpiad]

There are two types of "iron", kamacite and taenite. The goal is to etch out the kamacite to show the winmanstatten patterns.

[akcapr]

well, if u aske me id say theres one type of iron- Fe element. Are the "two types of iron" iron compounds or iron mixed with something?

[BenSon]

well, if u aske me id say theres one type of iron- Fe element. Are the "two types of iron" iron compounds or iron mixed with something?

My guess would be two different crystalline stuctures. Seeing as he's looking for patterns?

 

~Scott

[YT2095]

correct guess

 

of course the only problem is that Iron is Iron, regardless of it`s crystal structure, and so all would be affected the same

[entropydave]

i need nitric acid to etch a meteorite (iron)

 

ferric chloride is just as good - degrease a polished slice, use a swab of cotton wool to apply the ferric chloride and then rinse v. thoroughly with deionised water, then a rinse in 95% isoprop, then a gently bake at about 110- 120 deg c.

That'll work nicely!

[entropydave]

well, if u aske me id say theres one type of iron- Fe element. Are the "two types of iron" iron compounds or iron mixed with something?

Taenite is high in nickel, (>10% or so) Kamacite is lower in nickel - or the other way around!

[Guest loopie]

olmpiad - Why not buy nitric acid? So much simpler, or is it that you "can't"?

If you "can't", perhaps it's too dangerous for you to be handling, much less making.

[akcapr]

id say it dangerous and reactive and powerful. it can be bought however, but its often used to make explosives so its generally not sold much.

[woelen]

i need nitric acid to etch a meteorite (iron)

Metal etching can also be done very well with a mix of hydrogen peroxide and hydrochloric acid (muriatic acid).

 

Hydrogen peroxide is easy to obtain (3% concentration, but for hair bleaching 10% is available also). You can concentrate 3% H2O2 to 10% easily yourself by freezing the liquid for half the volume and keeping the liquid part. Repeat this two times.

 

Mix 1 part of 10% H2O2 with 1 part of 30% HCl and you have a perfect metal etching mix. It eats rust and it also (slowly) eats metal.

 

Although this mix is quite nasty, it is not nearly as nasty as concentrated nitric acid and the ingredients are much easier to obtain.

 

Do not store this mix in a closed bottle, as it slowly decomposes and may lead to high pressure. If you store it in a loosely capped bottle, then store it in an old barn or something, but not inside your house. The fumes are really corrosive and you would not like these to have in your house.

[akcapr]

wat acid is formed from that?

[jdurg]

I don't believe any special acid is formed. What you get is a strong oxidizer under acidic conditions, and any mixture of strong oxidizer and an acid is a VERY potent substance. Nitric acid is not really a very strong acid, but the nitrate ion in acidic conditions is a very potent oxidizer. As a result, nitric acid can dissolve most anything. Hydrochloric acid is a poor oxidizing agent, but if you mix it with a strong oxidizer (nitric acid or hydrogen peroxide), it becomes a very potent oxidizer. So whenever you mix a strong oxidizing agent like hydrogen peroxide with an acid, you wind up with the oxidizer under acidic conditions which results in a very corrosive and dangerous mixture.