Chemicals can be identified based on their characteristic properties. This is an updated version of my flame tests demo. I got the idea for this demo strangely enough from the AMC television show Breaking Bad. The main character in the show is a chemistry teacher, played by the terrific Bryan Cranston, (he also played Buzz Aldrin in From the Earth to the Moon). In the first episode he is in class showing the students how different chemicals burn different colors. He used spray bottles to disperse the chemicals across a Bunsen burner flame. I thought it was something that I definitely wanted to try out in the classroom, so I decided to give it a shot. I made the following solutions and put them in different spray bottles:
A. water only
B. 75 ml methyl alcohol only
C. 75 ml methyl alcohol, 4.5g of copper sulfate
D. 75 ml methyl alcohol, 4.5g of strontium chloride
E. 75 ml methyl alcohol, 4.5g of lithium chloride
Watch the video to see the results.
What color a substance burns is one property that can be used to identify a substance. Others include density, melting point, boiling point, hardness, etc. A flame test is definitely the most exciting property.
Isn’t that stuff like the kind of stuff they use in fireworks?
Yes, makers of fireworks have extensive knowledge of what chemicals burn what color. Here is a link with some more information about the chemistry of fireworks including what colors certain chemical produce when burned.
http://chemistry.about.com/od/fireworkspyrotechnics/a/fireworkcolors.htm