[Bill.D.Katt. (OP)]

The exothermic reaction between Al and KNO3 (a slow flash powder) oxidizes Al. If Al2O3 is one of the products, what are the others? A thick white smoke was released, I'm guessing it was some form of oxidized N. What is the balanced equation? Since there was no H involved, it seems that K2O must be included.

[lightarrow]

The exothermic reaction between Al and KNO3 (a slow flash powder) oxidizes Al. If Al2O3 is one of the products, what are the others? A thick white smoke was released, I'm guessing it was some form of oxidized N. What is the balanced equation? Since there was no H involved, it seems that K2O must be included.

It depends on the relative amounts. You could have:

2Al + KNO₃ → Al₂O₃ + K + ½N₂↑

or:

10Al + 6KNO₃ → 5Al₂O₃ + 3K₂O + 3N₂↑

or:

2Al + 2KNO₃ → Al₂O₃ + K₂O + 2NO↑

or:

...
...
...

[Bill.D.Katt. (OP)]

Could it really create elemental K? I didn't think that it would get hot enough to do so. And if it did, there would be a secondary reaction between the K and the Al2O3 right?

[Bored chemist]

At least one of the products will be potassium aluminate.
Very litle elemental K will be made; any that is wil react with the air.

[lightarrow]

Could it really create elemental K? I didn't think that it would get hot enough to do so.

Looking for standard enthalpy of formations of K₂O and Al₂O₃:

K₂O
http://webbook.nist.gov/cgi/cbook.cgi?ID=C12136457&Units=SI&Mask=2#Thermo-Condensed

Al₂O₃
http://webbook.nist.gov/cgi/cbook.cgi?ID=C1344281&Units=SI&Mask=2#Thermo-Condensed

we can infer that the reaction:

3K₂O + 2Al → Al₂O₃ +2K

has an enthalpy of -586.19 kJ/mol, that is, it's very exothermic.

Actually, you would be amazed of how strongly aluminium remove oxigen from chemicals; it removes oxygen from almost every oxide of elements; there are just a few exceptions, for example BeO, MgO, CaO, probably also Li₂O, BaO and no much more than these...

And if it did, there would be a secondary reaction between the K and the Al2O3 right?

Of course not, if the reaction A → B is very favoured, the opposite reaction B → A is very disfavoured (not sure of the english terms).