12\11\01

Dear Dexter School Board,

    I started with six possible powders that could be in the Mystery Powder, but it contained only three of them. I learned to test for acid using Phenol Red, test for base using Phenolphthalein, and test for starch using iodine. The Mystery Powder is a mixture of three powders: cornstarch, salt and baking soda. This is how I reached my conclusion.

    I did five tests, mixing the powder with oil, vinegar, water, alcohol and iodine. When iodine was mixed with the powder, it turned blackish- blue. That told me there was a starch in it because iodine is an indicator for starches. The only starch I had was cornstarch, which confirmed that cornstarch was in the mystery powder.

    I found out salt was in the mixture by mixing the mystery powder with alcohol. When I mixed the two together, it smelled bitter, and like disinfectant. That told me salt was in it because the results were the same when I mixed salt with alcohol and the mystery powder with alcohol.

    The last powder in the mixture was baking soda. When I mixed the mystery powder with vinegar, it bubbled and fizzed. I concluded baking soda was in it because baking soda was the only powder that fizzed when mixed with vinegar.

    The mystery powder came from the grocery store. The trucks that ship the items to other grocery stores in the county park in the alley right behind Dexter School. The powders are packed in big plastic sacks. The person who was loading the powders into the truck ripped the bags on the edge of the truck. The driver forgot to close the hatch in the back of the truck because he was in a hurry. When the driver turned onto School Street, all the powder flew out of the back of the truck and landed on the schoolyard. That is how the powder got there. Thank you for employing me. I have enjoyed the work.

THANKS,

            Sam