Mystery Powders

Dear Dexter School Board,

    Ever since you asked our class to help you ` figure out what the mystery powder on your playground was, we have been working long and hard to help you figure it out. We have come to the conclusion that we have figured it out. It is baking soda, salt and corn starch. This is how we know:

    First we had to analyze the powders by looking, smelling and feeling them. We then looked at the powders under a hand lens. Then our teacher, Mrs.Tate, gave us four liquids: water, vinegar, vegetable oil, and alcohol to mix with all the powders. We had to see if there were reactions. Did they dissolve or not? Did they get fizzy or something like that? We had to make sure we used fair tests of powder and liquids.

    For something more challenging, Mrs.Tate gave us iodine, phenolphthalein (PT) then phenol red (PR) and we had to test for starch, base, and acid. When we tested them with the powders, we realized that an acid would turn yellow and a base would turn pink. When we mixed a powder with iodine during our discovery phase, we learned that it would turn blue if it was a starch.

    We knew that salt was in the mix because it was the only crystalline product we had that was not an acid. We also knew baking soda was in it because it got fizzy when we mixed it with vinegar.

    Now it’s the moment of truth. How did the powder get there? I think that the bakery was going to bring some stuff to the lunch stand/ grocery store and there were two trucks. They went down School Street and went back up into the alley to deliver. They had to go on School Drive. After they parked the trucks, this HUGE wind came and blew all the powders onto the schoolyard!

By: Meghan