Dexter School
By Michaela
We have discovered what the mystery powder on your school playground is . We did
tests with it and figured out what it is. I t is cornstarch, salt and baking
soda. First we tested powders in cups called baking soda, salt, cornstarch,
citric acid, calcium carbonate, and sugar. We tested them with vinegar, alcohol,
oil and water. Baking soda and salt reacted with vinegar and alcohol.
They
fizzed. Corn starch and calcium carbonate reacted with all of them and got
mushy. I thought it was very disgusting.
Later on we tested all the powders with Phenolphthalein, Phenol Red and iodine.
Some reacted in a way that was very gross! Okay, first of all the
reaction of corn starch and iodine: they
turned black. The mixture followed the toothpick everywhere, like a magnet.
Other powders turned orange, red and brown. Citric acid fizzed with it.
We
tested the powders with Phenol Red and Phenolphthalein
and discovered which powders were acids and bases. The ones that turned
pink with Phenolphthalein were bases. The ones that turned pink with
Phenolphthalein were bases, and the ones that turned yellow with Phenol Red were
acids. Calcium carbonate and Baking soda were bases and corn starch and citric
acid were acids. The rest of the powders were neither of them. We also mixed all
of the liquids with Phenolphthalein and Phenol Red. Some fizzed, some
bubbled, and some turned white or clear.
Later on in
the unit we tested the Mystery Powder with some liquids. We got to choose from
water, alcohol, vinegar, oil, Phenol Red, Phenolphthalein and iodine.
First we
predicted what we would do and how it would react. We decided to test it with
all of them to compare how they reacted with them. We predicted Mystery Powder
would be all the powders so it would be an acid and a base.
The next time
we had Science we tested the mystery powder. We found out that it was an acid
and a base. We compared the reactions with the reactions that the other powders
had. We had only tested it with Phenol Red, Phenolphthalein, vinegar and iodine when
we discovered what it was. It bubbled a lot with vinegar which meant it had to
have baking soda or salt in it, or both.
We finally decided it
was baking soda, salt and cornstarch. We knew it was cornstarch because
cornstarch squeaks when you rub it between your fingers and so did the Mystery
Powder. Also, they're both acids. Then we knew it was salt and baking soda
because baking soda and salt were the only powders that reacted with vinegar and
alcohol like the Mystery Powder. They are all bases.
We think these
are some of the ways the powder could have gotten there: it could have come from
the Grocery Store
from a truck and the wind blew it out, or the Best-Buy Bakery could have had a
window open and it blew out the window. Or it could have fallen out of the window
of an apartment building.
I hope this information
helps you discover how the Mystery Powder got on your playground.
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Page created by Ms.
Marcell's class.
This page last updated: 08/28/04