Create a natural pH indicator using red cabbage juice. Test household substances to identify their pH levels as acidic, neutral, or basic.
If a substance changes the color of cabbage juice, then it can be identified as acidic or basic based on the resulting color.
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Chop red cabbage into small pieces.
Boil chopped cabbage in water for 10 minutes to extract juice.
Strain the cabbage pieces, collecting the juice in a container.
Pour cabbage juice into clear cups, filling each halfway.
Add a small amount of vinegar to the first cup and observe the color change.
Add a small amount of baking soda solution to the second cup and observe.
Add lemon juice to the third cup and observe the color change.
Use water in the fourth cup as a neutral control.
Record the colors and determine each solution's pH level.
The cabbage juice will change colors depending on the pH of the added substance, demonstrating its effectiveness as a natural pH indicator.
Type of substance tested
Color change of cabbage juice
Amount of cabbage juice, Amount of test substance, Cup size
Be cautious when handling boiling water and sharp knives.
Display a color chart for each pH level with examples.
Explain the chemistry of natural indicators.
Discuss how pH indicators are used in real-world applications.
Red cabbage contains a pigment that changes color at different pH levels.
Colors indicate pH levels; red/pink is acidic, green/blue is basic, and purple is neutral.
Yes, other anthocyanin-rich foods can also serve as pH indicators.
