MYSTERY POWDERS LAB: PHYSICAL AND CHEMICAL
CHANGES
PRE-LAB QUESTIONS:
1) Define physical property.
2) Define chemical property.
3) List four examples of physical properties.
4) List four examples of chemical properties.
5) What is a physical change? List three examples.
6) What is a chemical change?
7) Identify five possible observations that would indicate a chemical change/reaction.
MATERIALS:
Four Mystery powders
Chemplate Well
Droppers
Toothpicks
Water
Vinegar
Iodine
PROCEDURE:
1.
Using the appropriately labeled spoons, scoop up a ​
tiny​
bit of the following powders
and place them in the indicated wells in the spot plates:
Note: Be careful NOT to cross-contaminate!
2.
Powder “A”​
and place it in ​
wells 1, 5, and 9 ​
Use the “A” spoon!
3.
Powder “B”​
in ​
wells 2, 6, and 10​
. ​
Use the “B” spoon!
4.
Powder “C”​
in ​
wells 3, 7, and 11​
. ​
Use the “C” spoon!
5.
Powder “D” ​
in wells​
4, 8, and 12. ​
Use the “D” spoon!
MYSTERY POWDERS LAB: PHYSICAL AND CHEMICAL
CHANGES
6.
7.
8.
9.
10.
11.
Use a pipette to add ​
water​
into the wells ​
1, 2, 3, 4 so that it fills most of the well.
Stir each well with a clean toothpick. Do not reuse.
RECORD YOUR OBSERVATIONS IN THE DATA TABLE.
Use the pipette in the ​
vinegar​
bottle to add ​
10 drops​
of vinegar to the ​
powder​
in
wells 5, 6, 7, 8.​
Stir with ​
a clean toothpick​
for each well and ​
record observations.
Use the dropper in the ​
iodine ​
bottle to add ​
10 drops ​
of iodine to well ​
9, 10, 11, 12.
BE CAREFUL BECAUSE IODINE WILL STAIN​
. Stir with a new toothpick for each test.
Record observations.
Did you ​
RECORD ALL OBSERVATIONS? ​
Double check to make sure you did.
CLEAN UP: Rinse chemplate with water in the sink. Dry with paper towel.
TABLE 1: OBSERVATIONS
SUBSTANCE
UNMIXED
MIXED WITH
WATER
MIXED WITH
VINEGAR
MIXED WITH
IODINE
NAME THE
SUBSTANCE
POWDER
“A”
POWDER
“B”
POWDER
“C”
POWDER
“D”
MYSTERY POWDERS LAB: PHYSICAL AND CHEMICAL
CHANGES
TABLE 2: RESULTS
CHANGE:​
CIRCLE WHETHER EACH CHANGE WAS PHYSICAL OR CHEMICAL BASED ON
EVIDENCE OF A CHEMICAL REACTION
SUBSTANCE
A
B
C
D
Letter
SUBSTANCE
_______
_______
_______
_______
Name
CHANGE
CHANGE
CHANGE
CHANGE
MIXED WITH
PHYSICAL
PHYSICAL
PHYSICAL
PHYSICAL
H​
O
OR
OR
OR
OR
2​
CHEMICAL
CHEMICAL
CHEMICAL
CHEMICAL
CHANGE
CHANGE
CHANGE
CHANGE
MIXED WITH
PHYSICAL
PHYSICAL
PHYSICAL
PHYSICAL
VINEGAR
OR
OR
OR
OR
CHEMICAL
CHEMICAL
CHEMICAL
CHEMICAL
CHANGE
CHANGE
CHANGE
CHANGE
MIXED WITH
PHYSICAL
PHYSICAL
PHYSICAL
PHYSICAL
IODINE
OR
OR
OR
OR
CHEMICAL
CHEMICAL
CHEMICAL
CHEMICAL
DISCUSSION QUESTIONS:
1. All of the ​
unmixed​
substances were white powders. Which powders did you guess
correctly from just visual inspection?
2. What was the only ​
chemical property​
you tested? What is the definition of this
chemical property?
3. Describe the ​
difference between a physical change and a chemical change.
MYSTERY POWDERS LAB: PHYSICAL AND CHEMICAL
CHANGES
4. What clues did you see that indicated a chemical change?
5. You’re making grape Kool-Aid. What type of change is occurring? How do you know?
6. For the following determine if it is a physical or chemical ​
property​
. Write P or C for
each.
a. Reactivity
b. Density
c. Flammability
d. Luster
e. Hardness
f. pH
g. Color
h. Viscosity
i. Melting point & Boiling point
j. Brittle
k. Ductile
l. Malleable
m. Conductivity
7. For the following determine if it is a physical or chemical ​
change​
. Write P or C for each.
a. glass breaking
b. hammering wood together
c. a rusting bicycle
d. bread rising
e. separate sand from gravel
f. bleaching your hair
g. frying an egg
h. squeeze orange juice
i. boiling water
j. mixing salt and water
k. product gets hotter
l. water evaporating
m. cutting grass
n. burning leaves
o. fireworks exploding
p. cutting your hair
q. solid created from two liquids
r. mixing vinegar & baking soda
creates bubbles