Awesome pH Indicator with Red Cabbage Challenge
⚠️ Safety Warning
Adult supervision needed for boiling water. Some household chemicals should not be mixed together — test them in separate cups only.
All experiments require adult supervision.
Materials You'll Need
Gather these 5 items before starting
💡 Tip: Check off items as you gather them to stay organized!
Step-by-Step Instructions
Follow these 8 steps carefully
For this awesome version, chop the red cabbage into small pieces.
Have an adult pour boiling water over the cabbage in a bowl and let it steep for 15 minutes.
Strain out the cabbage pieces — the purple liquid is your pH indicator!
Pour equal amounts of cabbage juice into 5-6 clear cups.
Add a different test liquid to each cup — lemon juice, vinegar, baking soda water, soap, milk.
Watch each cup change to a different color!
Arrange the cups from most acidic (pink/red) to most basic (green/yellow).
Try testing other household liquids and predict if they are acids or bases.
✅ Remember: Take your time with each step and ask an adult for help if needed!
The Science Behind It 🔬
Red cabbage contains anthocyanins — natural pigments that change color depending on the pH (acidity or basicity) of a solution. In acidic solutions (like vinegar, pH 2-3), the indicator turns pink or red. In neutral solutions (like water, pH 7), it stays purple. In basic solutions (like soap, pH 9-10), it turns green, blue, or even yellow. Scientists use pH indicators all the time to test chemical solutions. The pH scale goes from 0 (very acidic) to 14 (very basic), with 7 being neutral! This variation explores the concept further by introducing new variables and measurements.