Mystery Powders Lab

Mystery Powders                            

Objective: To identify each of the powders through your observations and their physical or chemical changes.  Keep in mind the signs of the chemical changes that we have talked about.

Procedure:

1. Place a small amount of Mystery A into 4 three of your wells in your testing tray. 

2. Write down your observations of the color and texture for Mystery A.

3. Add about 3 drops of water to one well and observe what happens, write down your observations and write P for a physical change and C for a chemical change. You may mix it with a toothpick.

4. Add about 3 drops of vinegar to a new well and observe, write observations.

5. Add about 3 drops of iodine to your last well and observe, write observations.

6. Repeat the steps with Mystery B, C, D and E. Wash out your testing tray as needed; do not dry your testing tray.

7. Then ask Ms. Cotta to light your candle. Make 5 aluminum foil boats and place a small amount of Mystery A into one, B in a second one and so on.  Hold over the candle with the clothespin and write down observations. Do not forget to write P or C for type of change.  Throw away aluminum foil boats when finished and blow out candle.

	Mystery A	Mystery B	Mystery C	Mystery D	Mystery E
Color and texture
Reaction w/ water (P or C)
Reaction w/ vinegar  (P or C)
Reaction w/ iodine  (P or C)
Reaction when heated  (P or C)

What are each of the five mystery powders:

A ______________    B ____________   C _____________  D _________________   E _____________

Questions to Answer:

1. What substances reacted with vinegar? What is your evidence?

2. Which substance was not as soluble (dissolve) in water as well as the others?

3. What substances produced any odors when burned?

4. What substances had any movement when burned?

5. Why is it good lab practice not to taste or smell any substances found in the lab?

6. What is the definition of a chemical change?

7. Which of the substances underwent a chemical change? Give at least three examples. Explain why each is a chemical change.

8. What is the definition of a physical change?

9. Which of the substances underwent a physical change? Give at least three examples.  Explain why each is a physical change.

Procedure: Now you need to figure out what each of the mystery combinations are. #1 and #2 are both two of the substances mixed together. Use the same procedure that you used before.

	Color & texture	Reaction w/ water	Reaction w/ vinegar	Reaction w/ iodine	Reaction when heated
Mystery #1
Mystery #2

What are the two mystery powders that are mixed in Mystery #1? _______________________________________

What are the two mystery powders that are mixed in Mystery #2? _______________________________________