To identify the unknown chemical mixture (#757), a TLC analysis was conducted using three standards (aspirin, acetaminophen, and caffeine). A TLC plate was prepared by drawing an origin line and solvent front line with a pencil. Three spot were labeled A, B, and C. A sample of each standard was spotted on the analytical TLC plate approximately 1cm from the bottom of the plate. It was then enclosed in a jar filled with 2ml of 95% ethyl acetate- 5% acetic acid. (Another laboratory group conducted the same procedure but using 1:1 Hexanes: Ethyl Acetate as the developing solvent). After the TLC plate was developed until the solvent reached 1cm at its top; the plates were analyzed using UV light and the spots where recorded with a pencil. Then,
