Final Chemical Test

This afternoon the students took their final test for our chemical unit.  They were given a mystery mixture.  Their mixture could be a combination of the following chemicals:  alum, baking soda, baby powder, sugar and cornstarch.  Each group was given time to complete about 6 experiments with their mixture.  They heated them up, added vinegar to them, stirred them in water, and completed tasks with them.  After completing these experiments they compared them to their previous notes completed in past experiments.  Once they had a idea of what the two chemicals were that made up their mixture they move on to their chromebooks.  On their chromebooks they wrote a paragraph explaining what two chemicals made up their mixture and why they know it was these two.  This last part was completely independently.  Finally they sent their document to me.

My partner,Logan and I had mixture A .Logan and I think that mixture A is baking soda and cornstarch.  When we put  vinegar in it fizzled. When we put cabbage juice in it harden.Then Mr. Waara told us to heat it up mixture A and the outside turned black, but the inside was still white. So we think that mixture A is baking soda and cornstarch.
written by Austin

My partner Joey and I had mixture B. I think it’s sugar and cornstarch because when I mixed the vinegar it was starchy. When I let it sit it was sticky and hard to move. I think there is sugar in the mixture because in all the experiments the mixture was sticky.
Written by Tanner

I think experiment A is sugar and cornstarch, because when Mateo and I mixed water with it, it dissolved. When we mixed iodine with it, it turned purple. When we waited for a while it turned white. Then when we mixed vinegar with it and it turned sticky and was easy to move.
Written by Josephe

 My partner Sam and I had mixture C. I think my chemicals are baking soda and baby powder. I think one is baby powder because it smelled really strong and when I added iodine it was getting creamy. When I mixed baby powder by itself it got creamy too. After that I looked at the color of the chemical and it was the same as what it looked like by itself. Another chemical I think was mixed was baking soda. I think that because when I added vinegar it got bubbly, made sizzling sounds, and it all went where it wanted. Baking soda acted like soda because of the fizz it did when I added vinegar to it. When I added vinegar all by itself with baking soda it was about the same, because it was bubbly and the bubbles popped. Those are some reasons I think It's baking powder and baby powder.
Written by Allison