1. Cabbage Juice Lab
Purpose:
To test the pH of different solutions
using cabbage juice.

2. Why use cabbage juice?
• By boiling the red cabbage leaves, we
extracted a class of pigment molecules called
anthocyanins into solution. Anthocyanin
molecules will change their color depending
upon the pH of their environment and can
indicate the pH of a solution.

3. What is pH?
• The pH scale measures
how acidic or basic a
substance is.
• It ranges from 0 to 14.
• A pH of 7 is neutral.
• A pH less than 7 is
acidic, and a pH greater
than 7 is basic.

4. What should SOIL pH be to help plant
growth?
Most soils for plant If the pH of the soil is too
growth should be acidic, this may slow
around 6 to 7 (slightly down the
acidic to neutral) for decomposition process
optimal growth. If it is of bacteria.
too acidic, lime can be
added to raise the pH
level.

5. Investigation
• Identify each solution as either an acid, base,
or neutral.

6. Solution 1
Vinegar
pH: 3-4 (acid)

7. Solution 2
Soda
pH: 3 (acid)

8. Solution 3
Tap Water
pH: 7 (neutral)

9. Solution 4
Baking Soda
pH: 8-9 (base)

10. Solution 5
Milk
pH: 6 (acid)

11. Solution 6
Soapy Water
pH: 12 (base)

12. Solution 7
Lemon Juice
pH: 2-3 (acid)

13. Solution 8
Hand Sanitizer
pH: 7 (neutral)