From: RoyMayeda@aol.com
Date: Tue Jan 09 2001 - 22:25:21 PST
From: RoyMayeda@aol.com Message-ID: <27.fd8253e.278d5a51@aol.com> Date: Wed, 10 Jan 2001 01:25:21 EST Subject: re: Re: Pinhole Digest #548 - 01/05/01
Sally:
Not aware of any other easily available metals that burn easily in air. If
you don't need it to actually produce a flame, you can heat many commonly
available metals to high temperature in a crucible to oxidize them. (Not
sure what your equipment/chemical constraints are.) "Steel" (iron) wool will
burn, but it usually requires some "help" from extra oxygen or continued
heating to burn completely. Actually, burning the material in the open
allows a lot of convection currents which carry away much of the product,
making the determination of stoichiometric ratios less accurate anyway. We
usually have the students oxidize the Mg more gradually in a crucible with a
lid to minimize loss.
As for the decomposition, the hydrates are the easiest and safest to go with.
Copper (II) sulfate pentahydrate and magnesium sulfate heptahydrate (Epsom
salt) both give good results. The Epsom salt is cheaper and less toxic.
Heating sodium bicarbonate will produce sodium carbonate solid, but give off
both carbon dioxide and water as gases. (2NaHCO3 --> Na2CO3 + H2O + 2CO2)
You should be able to heat calcium carbonate (washing soda) to get calcium
oxide (lime) and carbon dioxide. (CaCO3 --> CaO + CO2) Heating potassium
chlorate will produce oxygen gas and leave potassium chloride behind, but the
melted potassium chlorate is an extremely dangerous oxidizer. I know we used
to all get to do this when I was in high school, but I'm surprised we
survived relatively unscathed! (2KClO3 --> 2KCl + 3O2)
Have fun. Play safe!
Roy Mayeda
Valley HS, Sacramento
RoyMayeda@aol.com
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