Science Buddies: "Ask an Expert"

hi I really like the project i am doing and everything is going well but then when i was typing some things up. Why is it when I am doing my project (by the way its crime scene chemistry) why do they use Iron, distilled water and iodine

Iron nitrate, distilled water, and Lugol's iodine are used in this particular situation because their combined results in the test will give you enough information to determine whether aspirin is present in any of the substances. Aspirin would be only a little bit soluble in water, would react with iron nitrate, and would react with Lugol's iodine. Pure sugar, salt, and cornstarch however, would not have the same pattern of results as aspirin.

In other situations (or if the first round of tests do not yield adequate results), forensic chemists might use other techniques or chemicals to analyze the properties of their test substances.

Hope this helps!

Karen Zhang