Ammonium Tri Iodide

[budullewraagh]

Budullewraagh, how would you set up this reaction at home? I'm thinking that you would need a bong-like container too put the KI solution in. Would you see the top so that the gas can't escape out? What state is the KCl in? (I imaging the I2 is a precipitate).

i would set up a closed chlorine apparatus with tubing to your KI soln container, which should also be closed off. make sure this apparatus can sustain a bit of pressure and be careful not to make the chlorine burst out, but that should work. your KCl will be aqueous

[TWJian]

I got the chemicals required,but I'm not going to try this since its extremly dangerous.

Nitrogen triiodide monoamine(NI3.NH2)exist in solution but once it crystalize out, it changes(therefore its more stable in solution,but don't count on it not detonating).

[budullewraagh]

it's much safer if you keep it wet

[Nave]

You will need:

Bunsen burner and asbestos square (or a hot plate)

Tripod and tin lid

Beaker, 250 ml

Separating funnel 100ml

Evaporating dish

 

Hydrogen peroxide 20 volume

Tetrachloromethane or dichloromethane

Distilled water

1M solution of Sulphuric acid

Supply of ribbon seaweed(Laminaria) - that you can

obtain a a biological supply store or from the

sea shore

 

Procedure

(You must work at a fume cupboard)

1-Collect and dry about a dozen 50cm lenghts of the

seaweed and heat them strongly on a tin recipient

until they are reduced to ash; probably it will

reduce a quite small quantity, about a spoonful.

2- Add to the ash 20 ml of distilled water

in a beaker, and heat the suspension until it boils.

3 - Filter the suspension

4 - Acidify the filtered with Sulphuric acid solution

5 - Add then the hydrogen peroxide solution

You will observe the formation of a brown color due

the iodine liberation from the iodine ions present

6- Transfer the mixture to a separating funnel

7 -Extract the Iodine with tetrachloro methane or other

solvent. The result is an organic solution of iodine.

8 - In order to obtain crystals , the solvent may be

allowed to evaporate at room temperature, by

placing it in an evaporating dish in a fume cupboard.

It will result crystals of iodine or rather gray-

black brilliant flakes.

 

hope this helps

[5614]

thanks nave... that's a great post.

 

once you have iodine (which i do) how do you get it to form NI3?

 

just put together some I2 + NH3 in a bottle and shake it or something??!?!?

 

and isnt household ammonia NH4OH or something - so how does that work?

[5614]

http://www.armory.com/~spcecdt/pyrotech/NI3incid.html

 

great site on an NI3 incident... ends well!

 

[r1dermon]

dont let too much dry up on you in one spot. slight breeze and kaboom. its fun stuff when its in small quantities. but too much is just asking for trouble.

[jdurg]

thanks nave... that's a great post.

 

once you have iodine (which i do) how do you get it to form NI3?

 

just put together some I2 + NH3 in a bottle and shake it or something??!?!?

 

and isnt household ammonia NH4OH or something - so how does that work?

 

 

NH4OH is kind of a misnomer. It's just another term for NH3 in water. (Techincally the ammonia does combine with the water to form NH4OH, but in reality it's just ammonia solvated by the water). I'm not even sure if anhydrous ammonia and iodine will give you NI3.

[5614]

well i've heard the NH4OH (common household version of ammonia) could be used in NI3 production.

 

anyway, so if you have NH4OH or NH3 and some I2 do you just pop em together in a glass container and wait for the to fully react (can take 20 or 30 mins)?

[jdurg]

Whenever I've made NI3 I've just used any old container and put the household ammonia (Which is a solution of ammonia gas in water, a.k.a. NH4OH) into the container and threw in some crushed up I2. I'd then throw in a few grains of KI to help the iodine dissolve, and let it sit for an hour or so while I'd go out and do something else. I would then pour out the solution through a coffee filter and let the 'muck' dry out FAR away from anything valuable or alive. I would also severely wash out the container with a ton of water and dispose of it someplace outside. (This way if there was any NI3 in there, the massive amount of water would dilute it so much that if it dried, there's wouldn't be a heckuva lot left to decompose).

[5614]

Not at all, things are more complicated than they seem. Traditionally, nitrogen triiodide is made by reacting iodine with aqueous ammonia solution. That does not produce NI3, an ammonia complex is obtained instead. This is either [NI3.NH3] or [NI3.(NH3)3'], and the ammonia cannot be removed from this.

so looking at the quote above does household ammonia aka ammonia hydroxide or NH4OH with I2 still produce a big bang when it is disturbed????

 

can you get NH3 from NH4OH ?

[jdurg]

NH4OH IS NH3!! People just say NH4OH because they think that a base MUST have the OH ion someplace in it. In reality, NH4OH does not exist in a pure form. NH3 exists in a pure form, but NH4OH is simply the name for NH3 dissolved in water. It's used to distinguish between ammonia gas and a solution of ammonia. When mixed with iodine, the end result is the same. The 'big bang' still exists because the same compound is made whether you're using household ammonia (Without any additives or colorants/perfumes added to it), or you're using chem-lab ammonia.

 

Actually, there is a slight difference between NH3 and NH4OH. When NH3 dissolves in water, it does slightly 'bind' to the water and temporarily forms the NH4OH compound. However, this isn't a very "stable" compound, so to speak, and will repeatedly dissociate into water and ammonia gas again. (That's why solutions of ammonia smell like ammonia. Because the gas is being given off).

[5614]

so there are weak bonds linking the OH in the NH4OH.. how would one go about breaking em and obtaining pure NH3 ???

 

because that site i quoted in my last post said that NH4OH and I2 would give either [NI3.NH3] or [NI3.(NH3)3] not pure NI3... so whilst it'd be good and ~80% if in theory one wanted pure NI3 from NH4OH how would you do it?

[budullewraagh]

hardly. the accepted formula is NH3(aq), not NH4OH. until recently it was NH4OH.

[5614]

ok, maybe im not getting my point clear... even if it is just accepted as NH3 aq that is great... but it is not pure NH3.... in fact it is NH4OH with some crappy little almost insignificant bonds with the OH.... however answer this:

 

1) is this true: NH4OH and I2 would give either [NI3.NH3] or [NI3.(NH3)3] not pure NI3

 

2) how do i extract NH3 (g) from NH4OH or NH3 (aq) ????

[budullewraagh]

no, what i am saying is it is never NH4OH. ever. it has recently been determined that any van der waals' forces that would form something like NH4OH are not significant.

1 is true to an extent

to get NH3(g) from NH3(aq), just bouil water

[5614]

to get NH3(g) from NH3(aq), just bouil water

 

but as NH3 is a gas (i think at room temp?) if you boil the water off then surely the NH3 would end up as a gas and float away too?

[jdurg]

but as NH3 is a gas (i think at room temp?) if you boil the water off then surely the NH3 would end up as a gas and float away too?

 

 

Yes, but there is NO OTHER WAY to remove the water since at room temperature NH3 is a gas. You have to cool it off pretty significantly, or compress it very well, in order for it to liquify.

[budullewraagh]

well, you could concentrate the NH3 by boiling the solution. water will boil off but the NH3 will remain aqueous even beyond the point of saturation

[jdurg]

well, you could concentrate the NH3 by boiling the solution. water will boil off but the NH3 will remain aqueous even beyond the point of saturation

 

 

Ummmm............ I'd like to see proof of that. It goes against logic and chemistry to say that a gas becomes more soluble in water as the temperature is raised. In fact, at a higher temperature the NH3 will be even more volatile and will leave the solution much easier. The only way to concentrate a solution of ammonia is to heat the solution to drive the NH3 out, and then collect that NH3 in a different vessel with a much smaller amount of water in it.

[budullewraagh]

im not saying it can be more soluble. what im saying is that it could become supersaturated, although saturation point depends on temperature

[jdurg]

Yes, but as the water boils gas bubbles of water will form which will cause the NH3 to leave. It's like putting a seed crystal into a supersaturated solution. As soon as that crystal is introduced, it all ppts out. With the ammonia gas, even if it did become supersaturated as soon as one 'seed' bubble forms, it will all evaporate out.

[budullewraagh]

3% isn't saturated

[CMN]

Just curious as to why the ammonium tri iodide is so stable what causes the explosion?

[jdurg]

Just curious as to why the ammonium tri iodide is so stable what causes the explosion?

 

Really, ammonium triiodide isn't stable at all. If you look at all the Nitrogen trihalides, the stability depends on the strength of the N-Halogen bond. NF3 is VERY stable because the nitrogen-fluorine bond is pretty strong. The N-Cl bond is weaker, N-Br is even weaker, and N-I is incredibly weak. As a result, that 'weakness' results in instability. Ammonium/Nitrogen triiodide is able to remain stable when wet, however, because the ammonia atoms are able to solidify that N-I bond. I think they help relieve the stress on the bond which allows it to remain intact. It still decomposes, but not at a high rate of speed. When the compound dries, any stability is lost. The compound becomes 'metastable', I'd say, meaning that it won't suddenly decompose unless provoked. Any slight provocation will cause the bonds to break and the compound to explode.

 

The reason for the explosion is because you have a solid reactant decomposing into multiple gaseous products and releasing a great deal of energy when doing so. (The products released are nitrogen gas, iodine gas, and some remnant ammonia gas as well). Any time you have more gas molecules forming than you have solid reactants decomposing, you have a great chance of an explosion. (Hence why TNT is a good explosive. The solid crystal decomposes into all gaseous products). Ammonium/Nitrogen Triiodide is classified as a High Explosive, I believe, due to the nature of its 'KABOOM'. It's just not used in the same manner as TNT, TNP, Nitroglycerin, etc. since there is really no way to transport the triiodide molecule intact, and generation on site takes way to long and is not 'cost effective'.

 

The decomposition is caused when one of the Nitrogen-Iodine bonds are broken. It takes very little energy to break that bond, so any slight movement will cleave it. I'm not 100% sure on this, but I think that when the bond is cleaved it forms a 'free radical' Iodine atom to form which then goes and causes another bond to cleave. Kind of like a chain reaction in nuclear fission. Once one molecule decomposes, it causes other molecules to decompose and so on and so on.