Purpose:

The purpose of this lab is for students to observe the changes in a material's physical properties after a chemical change has occurred. The results of the lab will allow students to "detect" the differences in a group of unknown white powders.

Procedure:

1. Create a data table.
   Prepare all materials for testing.
2. Label your watchplate "vinegar", "iodine" and "water"
3. Put about 1 ml of baking powder into 3 sections of the watchplate. To the first section add a drop of water. Observe.
4. Repeat procedure above two more times using iodine and vinegar. Record your observations in your data table.
5. Wash out your testing materials carefully. Rinse with plenty of water, you do not need to dry them.
6. Then put 1 ml baking soda into your watch plate, test with each of the liquids.
7. Repeat procedure for each of the white powders and record all observations.

Materials:

pens
water
watch plate
cups
droppers
iodine
vinegar
baking powder
baking soda
cornstarch
baby powder
safety goggles

Discussion Questions: (write these out in your lab book)

1. Describe in your own words why you had a variety of results.

2. Why do physical properties change when chemicals combine?

3. From your evidence what could you guess is the chemical composition of baking powder ?

4. Describe how you might use what you learned today in your "real life".

Need help ? check here Chem4Kids! Your Chemistry Website at the mixtures section.

To go beyond: (for an optional or portfolio lab, complete one of the activities below.)

Interested in more home labs? Check here home labs or you can with beakman and jax

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