madchemist
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strange zinc/magnesium reaction
okay, this is my first post so if i do anything wrong please inform me.
not too long ago i tried to alloy zinc and magnesium together. Needless to say, i was sucessful but something strange occured while making it. At one
point i allowed the magnesium/zinc alloy to heat quite a bit. the reaction that ensued was really odd. the magnesium appeared to ignite as though it
were forming magnesium oxide, you know when you burn it in air, the only thing was that both the zinc and magnesium ignited and i was left with a
yellow powder of some sort. does anyone know what this is because, i have no idea.
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I am a fish
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Did the yellow colour fade as the mixture cooled down? If so, this is due to zinc oxide. It is white when at room temperature, but yellow when hot
(due to a solid state phase transition).
1f `/0u (4|\\| |234d 7|-|15, `/0u |234||`/ |\\|33d 70 937 0u7 /\\/\\0|23.
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madchemist
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The yellow color didn't fade or as far as i can recall. I'm pretty sure it stayed.
I would suggest others to try this little experiment, it doesn't take too long.
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Esplosivo
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I would suggest others to try this little experiment, it doesn't take too long.
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I am pretty sure that quite a number of us here are not able to melt magnesium at a temp of 650 deg celcius and with an inert medium  
Theory guides, experiment decides.
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FrankRizzo
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There is really no need for an inert atmosphere when doing this experiment. Back in high school chemistry, a buddy and I did the same thing using a
bunsen burner and ceramic crucible. It's actually quite neat. If you heat the mixture to it's ignition point, it burns with a most lovely
pale-blue flame (zinc), and sends streamers of zinc oxide into the air above. The magnesium will ignite too in little "blisters" as the MgO
coating is pierced through. As to the yellow powder, I got the same stuff but didn't question as to what it was.
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unionised
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Like magnesium, zinc will burn in air if you get it hot enough. Burning Mg is presumably hot enough to ignite the zinc
The fumes from burning Zn are not good for you, so don't do this indoors.
My best guess for the yellow colour is the preseence of impurities (probably iron).
[Edited on 19-6-2004 by unionised]
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Esplosivo
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As an impurity I would mention lead. Lead (II) Oxide is yellow (when cold). If heated the yellow PbO turns red so this can be used to test for this
hypothesis if anyone does carry out this reaction. (The red colour turns back to yellow when PbO is left to cool again)
Theory guides, experiment decides.
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tantan
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From http://www.du.edu/~jcalvert/phys/zinc.htm
"If zinc oxide is breathed, the strange nervous
malady "oxide shakes" seems to result."
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axehandle
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"If zinc oxide is breathed, the strange nervous
malady "oxide shakes" seems to result."
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This would certainly explain my condition today, or perhaps it was the beer...
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unionised
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The thermochromism of lead oxide probably only works well for fairly pure samples.
[Edited on 21-6-2004 by unionised]
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