November 2024 Visit on Friday, November 15, 2024
Experiment Lead: Molly Sneddon
For our first SFA visit of the 2024-2025 school year at Murray Middle School, Molly led an experiment investigating chromatography! First, we discussed the meaning of the word “chromatography” as well as practical applications. We learned how it is applied in a chemistry setting to separate individual components from a mixture for analysis and quantification. For the experiment, we looked further into the technique of paper chromatography and thought about the roles of mobile phases, stationary phases, and capillary action in separation of components on paper.
The SFA team prepared the experiment by making three solutions of either water, isopropanol, or a 50:50 mixture of water and isopropanol. The team also cut copious amounts of filter paper into strips. Each student team was then able to investigate what colors are used in manufacturing to make up the hues of different brands of washable markers (Crayola vs Cra-Z-Art) and permanent markers (Sharpie and off-brand). Students marked dots on the lower half of the strips of paper and dipped them into the solution of their choice and watched the colors move and separate by capillary action up the paper. They quickly learned that colors like black and gray are not simply made of black or gray but are made up of many combinations of colors like purple, green, and blue! They also learned that dyes in washable markers and permanent markers have different affinities for each type of mobile phase based on their preference for water or organic solution. As the grand finale, students also got to test what colors go into M&M dyes; some M&Ms were eaten, too. :)
The SFA team had a wonderful time with the students in Mrs. Crowley’s class at Murray Middle School. We can’t wait to do it again in December!