Sunday, June 27, 2010

Chemistry Fun

Here's the result of my second annual attempt to make smoke bombs.

I say second annual because the score is currently chemicals one and Heath one. Last year's attempt did not work, and proved toxic. The formula for smoke bombs is quite simple. 3 parts potassium nitrate to 2 parts sugar. This mixture is heated in a pan until the sugar caramelizes. When it looks like peanut butter, drop 50 cent size dollops on to aluminum foil to cool. Better directions here.

Potassium nitrate( salt-peter) is the ingredient in stump remover. It's oxidizing properties help break down the wood. But, as I learned the hard way, not all stump removers use nontoxic potassium nitrate. I do not know what is in Bonide Stump Out but when I cooked it up I made a noxious cloud that I thought would lead to an embarrassing call to Poison Control.


I found that the smoke bombs worked better when I crushed the the stump remover. Notice how there are spherical pellets of potassium nitrate in the caramelized sugar. These still lit and worked, but not as well as the the next photo where the sugar and potassium nitrate form smooth discs of fun.
Since potassium nitrate is nontoxic, used as a food and toothpaste additive, I use my coffee grinder easily to turn the pellets into powder. (potassium nitrate is gives hot dogs and corned beef its pink color. If you listen you hear my neighbor John make a joke about heartburn and hot dogs.)
Finally here is what one of the smoke bombs looks like at night.

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