Kids CAMP
Investigating the
Change
Name:_________________
Summer 2005
Logbook
Investigating the Change
Lesson plan
Inquiry Level 1
I.
solution, basic solution or neutral
solution based on pH readings.
The students should be split into
small groups of 2-4 students. Each
group will combine the pairs of
substances one at a time and make
the observations that are asked of
them on the worksheet. They can
work within their group to determine
whether or not the interaction caused
a pH change. When they are
finished making their decision you
can assist them by asking questions
such as: Did you notice a color
change on the cabbage paper? I
forming a gas a chemical or physical
change? Is dissolving a solid into a
liquid a chemical or physical
change?
Topic Area
Discovering the differences between
chemical and physical changes and
understanding what is an acidic,
basic, or neutral solution
II.
Objectives
Students will observe a physical
change.
Students will combine certain solids
and liquids according to instructions.
Students will observe the interaction
between the materials.
Students will record and describe
what occurred.
IV.
Students will understand what is an
acidic, basic or neutral solution
based on pH readings.
III.
Science Skills
a. observing
b. recording data
c. inquiry
d. hypothesizing
Description of Activity
V.
This lesson can be used as either an
introduction to chemical and
physical changes or as a follow-up to
assess the understanding of the
material. In addition to
understanding chemical changes the
students are asked to assess
chemicals and chemical changes by
pH. The students should be able to
understand what is an acidic
Arkansas Science Standards
Physical System
PS.2.4
PS 3.1
PS 3.4
VI.
Materials
Physical change style:
Styrofoam cups
Sugar
Water
Large container to heat sugar and
water
Wooden sticks
Chemical change style:
Small paper or plastic cups
Ziploc bags
Small scoops
Pipets
Windex
Vinegar
Water
Cabbage water
Baking powder
Baking Soda
Sugar
Paper towels or filter paper
Paint palette
Sharpie pen
VI.
VIII. Key Question
What are the differences between a
chemical and physical change?
Management Suggestions
1. Lesson should take one 90
minute class.
2. Make groups between 2-4
students.
3. Go over instructions and
chemical and physical changes
before the students are allowed to
gather into groups.
Procedure
1. Separate class into groups
2. Hand out all materials
besides the substances they
will combine
3. Depending on whether or not
this is used as an introduction
of follow-up, review the
definitions and previous
examples of chemical and
physical changes
XI.
What the students will do
1. Instruct the students to do
one combination at a time
and then make
observations.
2. The students should
record their observations
in the chart and determine
if a change has occurred.
3. Repeat with each.
Prerequisite Skills
Students should be familiar with
basic properties of solids and liquids.
It will be helpful if they are already
familiar with certain other chemical
and physical changes such as
burning wood or tearing up a piece
of paper.
IX.
X.
XII.
Follow-up
Lead class discussion asking the
following questions:
1. Did you observe the differences
between chemical and physical
changes?
2. What do you think happened to
those that formed a gas?
3. What happens to the sugar when
it is dissolved into the water?
4. How can you tell the difference
between an acid, base or neutral
substances?
XIV. Enrichment
1. Students can try a variety of
different mixtures to determine if
there are chemical or physical
changes.
2. Students may look at different
mixtures that are present and
everyday life and discuss
whether they are chemical
changes or physical changes.
3. Students should have new
understanding how to determine
an acidic, neutral, or basic
solution is.
Investigating the Change
Physical Change Style
Rock Candy Investigation:
1.
2.
3.
4.
5.
6.
Use a 2 to 1 ratio of sugar to water solution ( i.e. 2 cups of sugar and 1 cup of water)
Heat up solution in a large pot.
Adult pour solution into student’s individual cups.
Student drops a thin wooden stick in cup.
Students will wait for crystal growth over 3 to 5 days or longer.
Students will record everyday what he or she sees in his or her cup.
Draw what you see!
Day 1
Day 2
Day 4
Day 5
Question: Do you see a physical change?
Day 3
Investigating the Change
Chemical Change Style
What are some signs that chemical change has occurred?
Gas
Bubbles
Color change
Red Cabbage project
Red cabbage contains a pigment molecule called flavin (an anthocyanin). This water-soluble pigment is also
found in apple skin, plums, poppies, cornflowers, and grapes. Very acidic solutions will turn anthocyanin a red
color. Neutral solutions result in a purplish color. Basic solutions appear in greenish-yellow. Therefore, it is
possible to determine the pH of a solution based on the color it turns the anthocyanin pigments in red cabbage
juice.
The color of the juice changes in response to changes in its hydrogen ion concentration. pH is the -log[H+].
Acids will donate hydrogen ions in an aqueous solution and have a low pH (pH < 7). Bases accept hydrogen
ions and have a high pH (pH > 7).
C. Cabbage pH paper
Break red cabbage leaves into small pieces and put into a pot of water. Heat the cabbage water on the stove for
15 minutes. Warning! This will be smelly! Drain the leaves over a container and keep the water! The water
should be a different color now. Cut pieces of paper towel into strips and put them into the cabbage water.
Spread the strips out and allow them to dry. Now test liquids or solutions to see if they are acidic or basic. To
test, place a dried strip into a solution. If the strip turns pink, the solution is acidic. If the strip turns green, the
solution is basic.
Here is a table of approximate colors of red cabbage indicator solution at different pH's. If you wish, make your
own chart, using chemicals of known pH.
2
4
6
8
10
12
pH
Color Red Purple Violet Blue Blue-Green Greenish Yellow







household ammonia (NH3)
baking soda (sodium bicarbonate, NaHCO3)
lemon juice (citric acid, C6H8O7)
vinegar (acetic acid, CH3COOH)
antacids (calcium carbonate, calcium hydroxide, magnesium hydroxide)
hydrochloric acid, HCl
sodium hydroxide, NaOH
Investigating the Change
Chemical Change Style
Investigation of wet stuff:
1.
2.
3.
4.
Smell each liquid and record what you smell.
Add one drop of each liquid onto the Cabbage paper. Record the color of what you see for each liquid.
Relate the color of the cabbage paper to the pH scale above and record the number for each liquid
Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the number from the pH is
Write BASE if the number from the pH is between 8-14.
Cabbage paper test
pH
2
4
6
8
10
12
Color
Red
Purple
Violet
Blue
Blue-Green
Greenish Yellow
Acidic-----------Acidic Neutral Basic-------------------------- Basic
Smell Test Cabbage paper test (color) pH Acid, Neutral, or Base
Water
Vinegar
Windex
Are the liquids different? If yes, then what makes them different?
Investigating the Change
Chemical Change Style
Investigation of white stuff with WATER:
1.
2.
3.
4.
Record how each of the white stuff looks like before you add the water.
Add water into bags 1,2,and 3 one at a time.
Record what you see after you add water to bags 1,2, and 3.
Add one drop from each of the white stuff and water mixture onto the Cabbage paper. Record the color
of what you see for each liquid.
5. Relate the color of the cabbage paper to the pH scale above and record the number for each liquid
6. Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the number from the pH is
Write BASE if the number from the pH is between 8-14.
Cabbage paper test
pH
2
4
6
8
10
12
Color
Red
Purple
Violet
Blue
Blue-Green
Greenish Yellow
Acidic-----------Acidic Neutral Basic-------------------------- Basic
Bags number
1,2,3
1. Sugar
2. Baking
Powder
3. Baking
soda
Notes:
How do they look
before you add
Water?
What happens
when you add
Water?
Cabbage
paper test
(color)
pH
Number
Acid,
Neutral, or
Base
Investigating the Change
Chemical Change Style
Investigation of white stuff with VINEGAR:
1.
2.
3.
4.
Record how each of the white stuff looks like before you add the vinegar.
Add vinegar into bags 4,5, and 6 one at a time.
Record what you see after you add vinegar to bags 4,5 and 6..
Add one drop from each of the white stuff and vinegar mixture onto the Cabbage paper. Record the
color of what you see for each liquid.
5. Relate the color of the cabbage paper to the pH scale above and record the number for each liquid
6. Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the number from the pH is
Write BASE if the number from the pH is between 8-14.
Cabbage paper test
pH
2
4
6
8
10
12
Color
Red
Purple
Violet
Blue
Blue-Green
Greenish Yellow
Acidic-----------Acidic Neutral Basic-------------------------- Basic
Bags
number
4,5,6
4. Sugar
5. Baking
Powder
6. Baking
soda
Notes:
How do they look
before you add
Vinegar?
What happens
when you add
Vinegar?
Cabbage
paper test
(color)
pH
Number
Acid,
Neutral, or
Base
Investigating the Change
Chemical Change Style
Investigation of white stuff with WINDEX:
1.
2.
3.
4.
Record how each of the white stuff looks like before you add the Windex.
Add Windex into bags 7, 8, and 9 one at a time.
Record what you see after you add Windex.
Add one drop from each of the white stuff and Windex mixture onto the Cabbage paper. Record the
color of what you see for each liquid.
5. Relate the color of the cabbage paper to the pH scale above and record the number for each liquid
6. Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the number from the pH is
Write BASE if the number from the pH is between 8-14.
Cabbage paper test
pH
2
4
6
8
10
12
Color
Red
Purple
Violet
Blue
Blue-Green
Greenish Yellow
Acidic-----------Acidic Neutral Basic-------------------------- Basic
How do they look
Bags number 7,8,9 before you add
Windex?
7. Sugar
8. Baking
Powder
9. Baking soda
Notes:
What happens
when you add
Windex?
Cabbage
paper test
(color)
pH
number
Acid,
Neutral, or
Base
Investigating the Change
Chemical Change Style
Comparison of all White stuff and Wet stuff combinations
1.
2.
3.
4.
Bags are numbered 1-9 that corresponds to the number on the paint palette.
Add 5 drops of Cabbage water to each well of the paint palette.
Add 2 drops of the white stuff and wet stuff combination from bag 1 to well 1.
Record the color from well 1. Relate the color of the cabbage paper to the pH scale above and record the
number for each liquid. Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the
number from the pH is 7. Write BASE if the number from the pH is between 8-14.
5. Add 2 drops of the white stuff and wet stuff combination from bag 2 to well 2.
6. Record the color from well 2. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
7. Add 2 drops of the white stuff and wet stuff combination from bag 3 to well 3.
8. Record the color from well 3. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
9. Add 2 drops of the white stuff and wet stuff combination from bag 4 to well 4.
10. Record the color from well 4. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
11. Add 2 drops of the white stuff and wet stuff combination from bag 5 to well 5.
12. Record the color from well 5. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
13. Add 2 drops of the white stuff and wet stuff combination from bag 6 to well 6.
14. Record the color from well 6. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
15. Add 2 drops of the white stuff and wet stuff combination from bag 7 to well 7.
16. Record the color from well 7. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
17. Add 2 drops of the white stuff and wet stuff combination from bag 8 to well 8.
18. Record the color from well 8. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
19. Add 2 drops of the white stuff and wet stuff combination from bag 9 to well 9.
20. Record the color from well 9. Record the color from well 1. Relate the color of the cabbage paper to the
pH scale above and record the number for each liquid. Write ACID if the number from the pH is
between 1-6. Write NEUTRAL if the number from the pH is 7. Write BASE if the number from the pH
is between 8-14.
21. Add 2 drops from the Mystery PH cup to well 10 and record the color you see. Record the color from
well 1. Relate the color of the cabbage paper to the pH scale above and record the number for each
liquid. Write ACID if the number from the pH is between 1-6. Write NEUTRAL if the number from
the pH is 7. Write BASE if the number from the pH is between 8-14.
Well
1:
SUGAR
& WATER
2: BAKING
POWDER &
WATER
3:
BAKNG
SODA &
WATER
4:
SUGAR &
VINEGAR
5:
BAKING POWDER
& VINEGAR
6:
BAKING
SODA &
VINEGAR
7:
SUGAR &
WINDEX
8: BAKING
POWDER &
WINDEX
9: BAKING
SODA &
WINDEX
Color
pH
Acid,
Neutral
or Base
Cabbage paper test
pH
2
4
6
8
10
12
Color
Red
Purple
Violet
Blue
Blue-Green
Greenish Yellow
Acidic-----------Acidic Neutral Basic-------------------------- Basic
10:
MYSTERY
pH
Investigating the Change
Invisible Ink project
By this time the students should know that the cabbage paper test is an indicator for determining what is an
acidic, basic or neutral solution. Another indicator is phenolphthalein solution. This solution makes a great
invisible ink. This solution will dry colorless.
Students will write his or her secret message on a piece of paper.
HOW CAN YOU SEE YOUR SECRET MESSAGE?
Rewetting with any moderately basic solution will turn it red, bringing out the message. If the base used is
aqueous ammonia (or window cleaner with ammonia), the ammonia will evaporate as the message dries:
Ammonia (liquid) → Ammonia (gas)
The pink color will disappear as the ammonia leaves the solution because the solution will no longer be basic.
When ammonia evaporates is that a physical change or a chemical change?
Other basic solutions, such as baking soda in water, will produce a “permanent”message when sprayed on the
phenolphthalein. To erase such a message, it must be resprayed with an acid such as vinegar, which will
neutralize the base.
Why using baking soda in water leaves the message permanent?
AMAZING