Dear Dexter School Board,
Our class has figured out what the mysterious powder in the Dexter School Yard was. We have discovered that the powder contains baking powder, salt and corn starch.
I think this powder was in the schoolyard because a delivery truck was heading down Market Street. It was delivering baking powder, salt and cornstarch to Best Buy Bakery. The driver saw a cat in front of him and skidded to a stop, saving the feline’s life, but spilling the contents of the truck. The driver, not noticing the powder was missing, continued driving. The powder, however, blew into the schoolyard.
For the past six weeks, we have been analyzing this powder. We had six powders to work with, but we didn’t know which of the six were in the mystery powder. In the end, we discovered that the mystery powder contained only three of the six we learned to analyze. We tested these powders with many liquids and we observed them. We recorded our results. Then we conducted the same tests on the mystery powder to see if any of the results matched.
We ruled things in and ruled things out For example, we labeled the powders by colors. The mystery powder and red both turned pink when we added phenolphthalein to test for base, so we ruled red in. We weren’t sure what the other two were, so we ruled things out. Purple is soluble, and so is blue, so they couldn’t be in the mystery powder. Also, there was no acid in the mystery powder and there was acid in the blue.
Corn starch mixed with iodine turned black, a test for starch. The mystery powder turned the same color, so we ruled corn starch in. By doing this, we reached a conclusion that the mystery powder contains baking powder, (red), salt (yellow) and corn starch (green).
We hope that you will let us know if you ever are unsure about any powders in the future.
The Super Scientists of the 4/5
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This page last updated: 08/28/04 .
Sincerely,
The Super Scientists of the 4/5