SAM4CH - 13-5-2006 at 12:27
I have magnesium composition powder from sounding bomb, how can I determine the composition of this powder using simple chemical method!!?
How can I test for Aluminum and Magnesium if I want to be sure that composite contain this metal or not?
[Edited on 13-5-2006 by SAM4CH]
woelen - 13-5-2006 at 14:13
Add a drop of some dilute HCl to a pinch of the composition. If it [I]immediately[/I] starts bubbling and becomes warm, then it contains magnesium
metal.
If it starts bubbling, but this takes some time, then it most likely contains aluminium metal. Aluminium also reacts with HCl, but the reaction does
not start at once. But unfortunately, there are quite some other metals, which also react with HCl.
A more reliable test for aluminium (in the absence of magnesium) is to add a drop of dilute HCl (e.g. 10% HCl will do, concentration is not really
critical), in which some copper sulfate, copper chloride or any other copper (II) salt is dissolved. If the sample starts fizzling at once with the
dilute HCl/copper(II) salt, and it does not fizzle at once with dilute HCl only, then you are quite sure that there is aluminium in the composition.
SAM4CH - 13-5-2006 at 15:14
It gives these results:
Al=-ve
Mg=-ve
Permanganate "with glycerin" =-ve
Methylene Blue "for perchlorate" = -ve
Conc. Sulfuric acid "for chlorate" : -ve
But I noted that it become very silver bright color "as mirror" and almost of it float on the top when it moisted with any liquid!!?
It is cracker composition... What is it contains???
[Edited on 13-5-2006 by SAM4CH]
enhzflep - 13-5-2006 at 16:47
Not really too sure how you could go about testing, it is also quite possible that the composition contains titanium. This would certainly be quite
inert to testing, and if i'm not mistaken - it would add a considerably larger safety margin than either Mg or Al would offer. As in spontaneous
reaction in presence of moisture, or from impact....
The_Davster - 13-5-2006 at 20:54
Assuming only Mg and Al are supposedly present:
Dissolve in acid(HCl), should be colorless, if Ti is present there will be a blue tinge, although that could indicate copper as well. Add lots and
lots of base, a white ppt should form(Mg(OH)2), filter out the ppt and slowly acidify the filtrate(I think HCl would be best), if a ppt forms (at any
point in the acidification, over acidification will cause the ppt to dissolve) then you have aluminum in your sample, if no ppt, it should be pure Mg
Alums such as magnesium aluminum sulfate(or other anion) may complicate things, hence my preference for HCl, I don't think chloride would cause alums
to form(can someone back me up on this? I have never really took an intrest in alums)
[Edited on 14-5-2006 by rogue chemist]
12AX7 - 13-5-2006 at 21:16
Thought alums happen mostly with K and NH3, not divalent ions??
Tim
SAM4CH - 14-5-2006 at 07:24
It was bind with plastic binder So, I dissolved it in acetone then dry and give me this results:
sulfuric acid: -ve "no thing"
conc. HCl: +ve "strong bubbling"
Gelycerin: -ve
dil. HCl: -ve
Its color is leaden and it generate a chlorine smell "may be HCl" while burning it. "I think it contain perchlorate or chlorate"
How can I detect exact composition "it is flash powder".?
a_bab - 14-5-2006 at 12:13
Try with vinegar. Ifitreacts (fizzle) itcontains Mg. If not, it's Al or Ti.