dpw@rayssd.UUCP (Darryl P. Wagoner) (09/24/86)
> > > >>Having made some nitrogen tri-iodide in MY younger, more impetuous days, > > ^^^^^^^^^^^^^^^^^^^ > > >I also made lots of nitrogen tri-iodide in my younger days, and I used > > ^^^^^^^^^^^^^^^^^^^ > > > > that's funny. i used to make ammonium tri-iodide, didn't know about > > nitrogen tri-iodide...wonder which is better? i had some pretty tremendous > > explosions with mine... > If you're talking about the stuff you get reacting 28% Ammonia (really > Ammonium Hydroxide) with Iodine cystals I think NI3 is closer to the > truth. The truth being that the inorganic chemistry of ammonia/ammonium > is rather screwy and complexes are more the rule than simple compounds. > > *WARNING* The above reaction is exothermic (heat producing) and has > blow up while still wet. > -- If there is any heat produce it is very little. It is NI3 (nitrogen tri-iodide). It does not blow up wet. If you get too much it's own weight will set it off. I have never seen anything that was so much as burnt from NI3. It does however stain, that may or may not evaporate. It is one of the better gags. -- Darryl Wagoner Raytheon Co.; Portsmouth RI; (401)-847-8000 x4089 best path {allegra|gatech|mirror|raybed2} ---------\ next best {linus|ihnp4|pyrbos} ---------------------->!rayssd!dpw if all else fails {brunix|cci632} -------------------------/
b-davis@utah-cs.UUCP (Brad Davis) (09/26/86)
In article <166@rayssd.UUCP> dpw@rayssd.UUCP (Darryl P. Wagoner) writes: >> > that's funny. i used to make ammonium tri-iodide, didn't know about >> > nitrogen tri-iodide...wonder which is better? i had some pretty tremendous >> > explosions with mine... >> If you're talking about the stuff you get reacting 28% Ammonia (really >> Ammonium Hydroxide) with Iodine cystals I think NI3 is closer to the >> truth. The truth being that the inorganic chemistry of ammonia/ammonium >> is rather screwy and complexes are more the rule than simple compounds. >> >> *WARNING* The above reaction is exothermic (heat producing) and has >> blow up while still wet. >> -- >If there is any heat produce it is very little. It is NI3 (nitrogen >tri-iodide). It does not blow up wet. If you get too much it's own weight >will set it off. I have never seen anything that was so much as burnt from >NI3. It does however stain, that may or may not evaporate. It is one of >the better gags. >-- A little chemistry for all of you computer jocks out there. The name is more properly ammmonium tri-iodide not nitrogen tri-iodide. I could tell you why it isn't NI3 but that isn't as important to the discussion. Ammonia is NH3. Iodine is I2. The ammonia is bound to the iodine with a property call hydrogen bonding. Hydrogen bonding comes about because the hydrogen atom (a single proton) sits out in space with only a little of the electron cloud surrounding it. This gives that part of the molecule a net positive charge. This will attract any other molecule that has a net negative charge at any point of its surface. Since iodine is a two atom balanced molecule the outside surfaces of the molecule are charged slightly negatively. This gives the following for ammonium tri-iodide, where the solid lines are real bonds and the dotted lines are hydrogen bonds. The hydrogen bonds are very unstable. When they break then you have some free iodine molecules that do the staining. Because the bonds are very weak the reaction is not very exothermic. Water is a polar molecule by build and is much better at hydrogen bonding than ammonia is. This is why water boils at a much higher temperature than ethanol which has a heavier molecule (C2H6 to H2O). If you add water to the mixture then the hydrogen bonds are strenghtened and the mixture becomes somewhat stable. When the water evaporates then the weak H-I bonds start to break on their own. O . . / \ . . H H .. H .. I-I .. H .. | | I-I .. H-N-H .. I-I .. H-N-H .. weak . . . . .. H .. I-I .. H .. | | I-I .. H-N-H .. I-I .. H-N-H .. stronger | | O O | | H .. I-I .. H -- Brad Davis {ihnp4, decvax, seismo}!utah-cs!b-davis b-davis@utah-cs.ARPA One drunk driver can ruin your whole day.