Stories tagged flame-test

Jul
04
2009

Awesome fireworks require a chemical bath

Fireworks color
Fireworks colorCourtesy Camera Slayer
Awesome Fourth of July fireworks can be viewed from our Science Museum of Minnesota each year during the Taste of Minnesota celebration. Fireworks are often shot over water to minimize fire danger. Ever wonder what kind of chemicals rain down into the Mississippi River during a fireworks display?

Chemical coloring

Part of learning chemistry is to understand what is called the flame test. Unknown chemical compounds, when heated in a flame, will generate different colors. Lithium yields red, copper gives blue or blue-green, sodium gives yellow, aluminum and titanium produce the whites.

Making fireworks more green

Chemists are attempting to make fireworks less harmful to the environment.

Perchlorates, which are used to help the fireworks’ fuel burn, were named in an EPA health advisory earlier this year (which recommended a maximum of 15 micrograms per liter of drinking water), as they have been linked to disruption of the thyroid gland.Scientific American

A 2007 U.S. Environmental Protection Agency (EPA) study found that perchlorates spiked by up to 1000 times normal after the fireworks display and took 20 to 80 days to return to normal depending on surface temperatures.

How to make fireworks whistle, crackle, and pop

Click this link where Live Science explains some of the strange ingredients in fireworks like:

"chemists add bismuth trioxide to the flash powder to get that crackling sound, dubbed "dragon eggs." Ear-splitting whistles take four ingredients, including a food preservative and Vaseline.
Tubes, hollow spheres, and paper wrappings work as barriers to compartmentalize the effects. More complicated shells are divided into even more sections to control the timing of secondary explosions.